High resolution computed tomography of the middle ear

International Nuclear Information System (INIS)

Ikeda, Katsuhisa; Sakurai, Tokio; Saijo, Shigeru; Kobayashi, Toshimitsu

1983-01-01

High resolution computed tomography was performed in 57 cases with various middle ear diseases (chronic otitis media, otitis media with effusion, acute otitis media and atelectasis). Although further improvement in detectability is necessary in order to discriminate each type of the soft tissue lesions, CT is the most useful method currently available in detecting the small structures and soft tissue lesions of the middle ear. In particular, the lesions at the tympanic isthmus and tympanic fold could very clearly be detected only by CT. In acute otitis media, lesions usually started in the attic and spread to the mastoid air cells. In otitis media with effusion, the soft tissue shadow was ovserved in the attic and mastoid air cell. CT is valuable in diagnosis, evaluation of the treatment and prognosis, and analysis of pathophysiology in the middle ear diseases. (author)

High-resolution x-ray computed tomography to understand ruminant phylogeny

Science.gov (United States)

Costeur, Loic; Schulz, Georg; Müller, Bert

2014-09-01

High-resolution X-ray computed tomography has become a vital technique to study fossils down to the true micrometer level. Paleontological research requires the non-destructive analysis of internal structures of fossil specimens. We show how X-ray computed tomography enables us to visualize the inner ear of extinct and extant ruminants without skull destruction. The inner ear, a sensory organ for hearing and balance has a rather complex three-dimensional morphology and thus provides relevant phylogenetical information what has been to date essentially shown in primates. We made visible the inner ears of a set of living and fossil ruminants using the phoenix x-ray nanotom®m (GE Sensing and Inspection Technologies GmbH). Because of the high absorbing objects a tungsten target was used and the experiments were performed with maximum accelerating voltage of 180 kV and a beam current of 30 μA. Possible stem ruminants of the living families are known in the fossil record but extreme morphological convergences in external structures such as teeth is a strong limitation to our understanding of the evolutionary history of this economically important group of animals. We thus investigate the inner ear to assess its phylogenetical potential for ruminants and our first results show strong family-level morphological differences.

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

OpenAIRE

Kakinuma, Ryutaro; Moriyama, Noriyuki; Muramatsu, Yukio; Gomi, Shiho; Suzuki, Masahiro; Nagasawa, Hirobumi; Kusumoto, Masahiko; Aso, Tomohiko; Muramatsu, Yoshihisa; Tsuchida, Takaaki; Tsuta, Koji; Maeshima, Akiko Miyagi; Tochigi, Naobumi; Watanabe, Shun-ichi; Sugihara, Naoki

2015-01-01

Purpose: The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods: This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm × 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm × 16 or 0.5 mm × 64 detector-row CT scanner operating at 150 mAs. Images fr...

High resolution computed tomography of the post partum pituitary gland

International Nuclear Information System (INIS)

Hinshaw, D.B.; Hasso, A.N.; Thompson, J.R.; Davidson, B.J.

1984-01-01

Eight volunteer post partum female patients were examined with high resolution computed tomography during the week immediately after delivery. All patients received high dose (40-70 gm) intravenous iodine contrast administration. The scans were examined for pituitary gland height, shape and homogeneity. All of the patients had enlarged glands by the traditional standards (i.e. gland height of 8 mm or greater). The diaphragma sellae in every call bulged upward with a convex domed appearance. The glands were generally inhomogeneous. One gland had a 4 mm focal well defined area of decreased attenuation. Two patients who were studied again months later had glands which had returned to ''normal'' size. The enlarged, upwardly convex pituitary gland appears to be typical and normal for the recently post partum period. (orig.)

Noninvasive Characterization of Indeterminate Pulmonary Nodules Detected on Chest High-Resolution Computed Tomography

Science.gov (United States)

2017-10-01

Chest High- Resolution Computed Tomography 5b. GRANT NUMBER W81XWH-15-1-0110 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Fabien Maldonado 5d. PROJECT...Selection of cancer cases and controls, flowcharts : Screen-detected lung cancers (N=649) Adenocarcinomas (N=353) Squamous cell carcinomas (N=136...during the process, and I hope everyone has a nice weekend! Best, Liz …… Elizabeth S. Moses, Ph.D. | Scientific Program Manager, DECAMP Boston

Pulmonary paracoccidioidomycosis: A case report with high-resolution computed tomography findings

Directory of Open Access Journals (Sweden)

M. Armas

2012-07-01

Full Text Available Paracoccidioidomycosis is a systemic mycosis which is endemic in rural areas of Latin America, an important European source of immigrants and a growing European touristic destination as well, with most cases occurring in Brazil, Argentina, Venezuela and Colombia. The authors report a case of a 43-year-old man who previously worked in Venezuela and is living in Portugal for 8 years, presenting with a single cutaneous lesion. Despite the absence of valuable respiratory complaints, severe lung damage was found with high-resolution computed tomography (HRCT. Biopsy of the cutaneous lesion and mycologic sputum examination were performed revealing Paracoccidioides brasiliensis infection. Resumo: A Paracoccidioidomicose é uma micose sistémica endémica nas áreas rurais da América Latina, uma fonte importante de imigrantes e destino de emigração e turismo europeu, a maioria dos casos ocorrendo no Brasil, Argentina, Venezuela e Colômbia. Os autores descrevem o caso clínico de um paciente com 43 anos, anteriormente emigrado na Venezuela e residente em Portugal há 8 anos, que se apresenta com lesão cutânea isolada. Embora sem queixas relevantes do foro respiratório, apresentava extensas lesões do parênquima pulmonar caracterizadas por tomografia computorizada de alta resolução (TCAR. Foi realizada biópsia da lesão cutânea e exame micológico da expetoração que revelaram infeção por Paracoccidioides brasiliensis (PB. Keywords: Paracoccidioidomycosis, Paracoccidioides brasiliensis, Pulmonary fibrosis, High-resolution computed tomography, Palavras-chave: Paracoccidioidomicose, Paracoccidioides brasiliensis, Fibrose pulmonar, Tomografia computorizada de alta resolução

A study with high resolution computed tomography of bone destruction in cholesteatoma

International Nuclear Information System (INIS)

Kikuchi, Shigeru; Yamaso, Tatsuya; Higo, Ryusaburo; Senba, Tetsuo; Iinuma, Yoshitaka.

1992-01-01

The modes and incidences of bone destruction in the middle ear cholesteatoma were evaluated by high resolution computed tomography, comparing with chronic otitis media with central perforation (COM) as control. The head of the malleus, the body and long process of the incus were more markedly destroyed in cholesteatoma than in COM with statistical significance. With the further extension of cholesteatoma into the antrum, the tegmen of the aditus ad antrum, the lateral semicircular canal, the handle of the malleus and the Korner's septum were involved in bone destruction. (author)

Quantitative image analysis of vertebral body architecture - improved diagnosis in osteoporosis based on high-resolution computed tomography

International Nuclear Information System (INIS)

Mundinger, A.; Wiesmeier, B.; Dinkel, E.; Helwig, A.; Beck, A.; Schulte Moenting, J.

1993-01-01

71 women, 64 post-menopausal, were examined by single-energy quantitative computed tomography (SEQCT) and by high-resolution computed tomography (HRCT) scans through the middle of lumbar vertebral bodies. Computer-assisted image analysis of the high-resolution images assessed trabecular morphometry of the vertebral spongiosa texture. Texture parameters differed in women with and without age-reduced bone density, and in the former group also in patients with and without vertebral fractures. Discriminating parameters were the total number, diameter and variance of trabecular and intertrabecular spaces as well as the trabecular surface (p < 0.05)). A texture index based on these statistically selected morphometric parameters identified a subgroup of patients suffering from fractures due to abnormal spongiosal architecture but with a bone mineral content not indicative for increased fracture risk. The combination of osteodensitometric and trabecular morphometry improves the diagnosis of osteoporosis and may contribute to the prediction of individual fracture risk. (author)

Breast tumor segmentation in high resolution x-ray phase contrast analyzer based computed tomography.

Science.gov (United States)

Brun, E; Grandl, S; Sztrókay-Gaul, A; Barbone, G; Mittone, A; Gasilov, S; Bravin, A; Coan, P

2014-11-01

Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer based phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure's possible applications. A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.

High resolution computed tomography in patients with various forms of systemic sclerosis

International Nuclear Information System (INIS)

Lewszuk, A.; Rozycki, J.; Tarasow, E.; Kowal-Bielecka, O.

2008-01-01

Pulmonary lesions are, besides renal and cardiac complications, one of the main causes of mortality among patients with systemic sclerosis (scleroderma). Pathologic changes in the respiratory system take the form of interstitial fibrosis clinically manifested by progressive exertion dyspnea and abnormalities of respiratory restriction type in functional tests. The aim of the study was systematization of pulmonary lesion symptomatology in conventional chest radiography and high resolution computed tomography (HRCT) in patients with various forms of scleroderma, as well as determination of the frequency and localization of the particular lesion types. The study was carried out in a group of 49 patients with systemic sclerosis (47 women and 2 men), who underwent conventional radiography and high resolution computed tomography of the chest. In patients with systemic sclerosis, HRCT revealed most frequently interstitial changes of ground glass type, as well as linear and reticular opacities, whereas bronchiectasis and honeycombing type lesions were less frequent. Pulmonary lesions were seen with increasing frequency towards the lung base and were localized mainly in the posterior, inferior and peripheral parts of the lungs. Comparison of the patients with limited and diffuse scleroderma demonstrated that the diffuse form is associated with more frequent involvement of the respiratory system and more advanced pulmonary lesions. The observed characteristics of pulmonary lesions show similarity between interstitial lung disease in the course of systemic sclerosis and nonspecific interstitial pneumonia (NSIP), which supports classification of interstitial lung disease associated with scleroderma as belonging to that group of interstitial inflammations. (author)

High-resolution computed tomography of cholesteatoma of the middle ear

International Nuclear Information System (INIS)

Ishii, Kiyoshi; Fukusumi, Akio; Okudera, Toshio; Kato, Toshihiko; Soda, Toyoji

1988-01-01

The high-resolution computed tomography (CT) appearances of 72 consecutive cases (92 ears) of chronic otomastoiditis were reviewed. The cholesteatomas were verified surgically and/or otologically in 35 of these 92 ears. Discussion was made with special emphasis on the differential diagnosis of cholesteatoma of the middle ear from the non-cholesteatoma otitis media. The CT findings suggestive of cholesteatoma were as follows: the definitive findings was of a soft-tissue opacity filling Purssak's space, with a medial displacement of the malleus and the incus; the possible findings were 1) a bony erosion of the wall of the middle ear cavity, 2) a partial or complete disappearance of the malleus and/or the incus, and 3) an opacification of Purssak's space and the superomedial aspect of the external auditory meatus. (author)

Breast tumor segmentation in high resolution x-ray phase contrast analyzer based computed tomography

Energy Technology Data Exchange (ETDEWEB)

Brun, E., E-mail: emmanuel.brun@esrf.fr [European Synchrotron Radiation Facility (ESRF), Grenoble 380000, France and Department of Physics, Ludwig-Maximilians University, Garching 85748 (Germany); Grandl, S.; Sztrókay-Gaul, A.; Gasilov, S. [Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, 81377 Munich (Germany); Barbone, G. [Department of Physics, Harvard University, Cambridge, Massachusetts 02138 (United States); Mittone, A.; Coan, P. [Department of Physics, Ludwig-Maximilians University, Garching 85748, Germany and Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, 81377 Munich (Germany); Bravin, A. [European Synchrotron Radiation Facility (ESRF), Grenoble 380000 (France)

2014-11-01

Purpose: Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. Methods: The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer based phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure’s possible applications. Results: A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. Conclusions: The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.

Computed tomography with selectable image resolution

International Nuclear Information System (INIS)

Dibianca, F.A.; Dallapiazza, D.G.

1981-01-01

A computed tomography system x-ray detector has a central group of half-width detector elements and groups of full-width elements on each side of the central group. To obtain x-ray attenuation data for whole body layers, the half-width elements are switched effectively into paralleled pairs so all elements act like full-width elements and an image of normal resolution is obtained. For narrower head layers, the elements in the central group are used as half-width elements so resolution which is twice as great as normal is obtained. The central group is also used in the half-width mode and the outside groups are used in the full-width mode to obtain a high resolution image of a body zone within a full body layer. In one embodiment data signals from the detector are switched by electronic multiplexing and in another embodiment a processor chooses the signals for the various kinds of images that are to be reconstructed. (author)

Functional high-resolution computed tomography of pulmonary vascular and airway reactions

International Nuclear Information System (INIS)

Herold, C.J.; Johns Hopkins Medical Institutions, Baltimore, MD; Brown, R.H.; Johns Hopkins Medical Institutions, Baltimore, MD; Johns Hopkins Medical Institutions, Baltimore, MD; Wetzel, R.C.; Herold, S.M.; Zeerhouni, E.A.

1993-01-01

We describe the use of high-resolution computed tomography (HRCT) for assessment of the function of pulmonary vessels and airways. With its excellent spatial resolution, HRCT is able to demonstrate pulmonary structures as small as 300 μm and can be used to monitor changes following various stimuli. HRCT also provides information about structures smaller than 300 μm through measurement of parenchymal background density. To date, sequential, spiral and ultrafast HRCT techniques have been used in a variety of challenges to gather information about the anatomical correlates of traditional physiological measurements, thus making anatomical-physiological correlation possible. HRCT of bronchial reactivity can demonstrate the location and time course of aerosol-induced broncho-constriction and may show changes not apparent on spirometry. HRCT of the pulmonary vascular system visualized adaptations of vessels during hypoxia and intravascular volume loading and elucidates cardiorespiratory interactions. Experimental studies provide a basis for potential clinical applications of this method. (orig.) [de

High-resolution coded-aperture design for compressive X-ray tomography using low resolution detectors

Science.gov (United States)

Mojica, Edson; Pertuz, Said; Arguello, Henry

2017-12-01

One of the main challenges in Computed Tomography (CT) is obtaining accurate reconstructions of the imaged object while keeping a low radiation dose in the acquisition process. In order to solve this problem, several researchers have proposed the use of compressed sensing for reducing the amount of measurements required to perform CT. This paper tackles the problem of designing high-resolution coded apertures for compressed sensing computed tomography. In contrast to previous approaches, we aim at designing apertures to be used with low-resolution detectors in order to achieve super-resolution. The proposed method iteratively improves random coded apertures using a gradient descent algorithm subject to constraints in the coherence and homogeneity of the compressive sensing matrix induced by the coded aperture. Experiments with different test sets show consistent results for different transmittances, number of shots and super-resolution factors.

High-resolution PET [Positron Emission Tomography] for Medical Science Studies

Science.gov (United States)

Budinger, T. F.; Derenzo, S. E.; Huesman, R. H.; Jagust, W. J.; Valk, P. E.

1989-09-01

One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging.

Intrathoracic manifestations of collagen vascular diseases on high-resolution chest computed tomography

Energy Technology Data Exchange (ETDEWEB)

Silva, C. Isabela S. [University of British Columbia, Vancouver (Canada). Vancouver General Hospital]. E-mail: isabela.silva@vch.ca; Mueller, Nestor L. [University of British Columbia, Vancouver (Canada). Vancouver General Hospital. Dept. of Radiology

2008-05-15

Intrathoracic manifestations of collagen vascular diseases are very common. The frequency of intrathoracic manifestations and the patterns of abnormality are variable depending on the type of collagen vascular disease and may simultaneously involve one or more of the following: lung parenchyma, airways, pulmonary vessels, pericardium, and pleura. The most common pulmonary manifestations are diffuse interstitial pneumonia and pulmonary hypertension which together represent the main causes of morbidity and mortality of these patients. Pulmonary, airway and pleural involvement may also be secondary to the disease therapy, or result from bacterial pneumonia or opportunistic infection. In the present review, the authors summarize the main intrathoracic manifestations of collagen vascular diseases and the differential diagnosis on high-resolution chest computed tomography. (author)

High-resolution short-exposure small-animal laboratory x-ray phase-contrast tomography

Science.gov (United States)

Larsson, Daniel H.; Vågberg, William; Yaroshenko, Andre; Yildirim, Ali Önder; Hertz, Hans M.

2016-12-01

X-ray computed tomography of small animals and their organs is an essential tool in basic and preclinical biomedical research. In both phase-contrast and absorption tomography high spatial resolution and short exposure times are of key importance. However, the observable spatial resolutions and achievable exposure times are presently limited by system parameters rather than more fundamental constraints like, e.g., dose. Here we demonstrate laboratory tomography with few-ten μm spatial resolution and few-minute exposure time at an acceptable dose for small-animal imaging, both with absorption contrast and phase contrast. The method relies on a magnifying imaging scheme in combination with a high-power small-spot liquid-metal-jet electron-impact source. The tomographic imaging is demonstrated on intact mouse, phantoms and excised lungs, both healthy and with pulmonary emphysema.

Resolution, sensitivity, and in vivo application of high-resolution computed tomography for titanium-coated polymethyl methacrylate (PMMA) dental implants

NARCIS (Netherlands)

Cuijpers, V.M.J.I.; Jaroszewicz, J.; Anil, S.; Al Farraj Aldosari, A.; Walboomers, X.F.; Jansen, J.A.

2014-01-01

OBJECTIVES: The aims of this study were (i) to determine the spatial resolution and sensitivity of micro- versus nano-computed tomography (CT) techniques and (ii) to validate micro- versus nano-CT in a dog dental implant model, comparative to histological analysis. MATERIAL AND METHODS: To determine

Using x-ray computed tomography in hydrology: Systems, resolutions, and limitations

DEFF Research Database (Denmark)

Wildenschild, Dorthe; Hopmans, J.W.; Vaz, C.M.P.

2002-01-01

media, obtained with different scanning systems and sample sizes, to illustrate advantages and limitations of these various systems, including topics of spatial resolution and contrast. In addition, we present examples of our most recent three-dimensional high-resolution images, for which......A combination of advances in experimental techniques and mathematical analysis has made it possible to characterize phase distribution and pore geometry in porous media using non-destructive X-ray computed tomography (CT). We present qualitative and quantitative CT results for partially saturated...

The Spectrum of Presentations of Cryptogenic Organizing Pneumonia in High Resolution Computed Tomography

International Nuclear Information System (INIS)

Mehrian, Payam; Shahnazi, Makhtoom; Dahaj, Ali Ahmadi; Bizhanzadeh, Sorour; Karimi, Mohammad Ali

2014-01-01

Various radiologic patterns of cryptogenic organizing pneumonia (COP) in X-rays have been reported for more than 20 years, and later, in computed tomography scans. The aim of the present study was to describe the spectrum of radiologic findings on high resolution computed tomography (HRCT) scans in patients with COP. HRCT scans of 31 sequential patients (mean age: 54.3±11 years; 55% male) with biopsy-proven COP in a tertiary lung center between 2009 and 2012 were reviewed by two experienced pulmonary radiologists with almost perfect interobserver agreement (kappa=0.83). Chest HRCTs from the lung apex to the base were performed using a 16-slice multi-detector CT scanner. The most common HRCT presentation of COP was ground-glass opacity (GGO) in 83.9% of cases, followed by consolidation in 71%. Both findings were mostly asymmetric bilateral and multifocal. Other common findings were the reverse halo (48.4%), parenchymal bands (54.8%) and subpleural bands (32.3%). Pulmonary nodules were found in about one-third of patients and were frequently smaller than 5 mm in diameter. Both GGOs and consolidations were revealed more often in the lower lobes. The main presentations of COP on HRCT include bilateral GGOs and consolidations in the lower lobes together with the reverse halo sign

Reversible bronchial dilatation in children: comparison of serial high-resolution computer tomography scans of the lungs

Energy Technology Data Exchange (ETDEWEB)

Gaillard, E.A. E-mail: erol.gaillard@lwh-tr.nwest.nhs.uk; Carty, H.; Heaf, D.; Smyth, R.L

2003-09-01

Introduction: bronchiectasis is generally considered irreversible in the adult population, largely based on studies employing bronchography in cases with a significant clinical history. It is assumed, that the same is true for children. Few studies have examined the natural history of bronchiectasis in children and diagnostic criteria on high-resolution computer tomography of the lungs are derived from studies on adults. Frequently, bronchiectasis is reported in children in cases where localised bronchial dilatation is present, incorrectly labelling these children with an irreversible life-long condition. Objective: to evaluate changes in appearance of bronchial dilatation, unrelated to cystic fibrosis in children, as assessed by sequential high-resolution computer tomography (HRCT) of the lungs. Methods: the scans of 22 children with a radiological diagnosis of bronchiectasis, seen at Alder Hey Children's Hospital between 1994 and 2000, who had at least two CT scans of the lungs were reviewed by a single radiologist, who was blinded to the original report. Results: following a median scan interval of 21 months (range 2-43), bronchial dilatation resolved completely in six children and there was improvement in appearances in a further eight, with medical treatment alone. Discussion: a radiological diagnosis of bronchiectasis should be considered with caution in children as diagnostic criteria derived from studies in adults have not been validated in children and the condition is generally considered irreversible.

Spectrum of high-resolution computed tomography imaging in occupational lung disease.

Science.gov (United States)

Satija, Bhawna; Kumar, Sanyal; Ojha, Umesh Chandra; Gothi, Dipti

2013-10-01

Damage to the lungs caused by dusts or fumes or noxious substances inhaled by workers in certain specific occupation is known as occupational lung disease. Recognition of occupational lung disease is especially important not only for the primary worker, but also because of the implications with regard to primary and secondary disease prevention in the exposed co-workers. Although many of the disorders can be detected on chest radiography, high-resolution computed tomography (HRCT) is superior in delineating the lung architecture and depicting pathology. The characteristic radiological features suggest the correct diagnosis in some, whereas a combination of clinical features, occupational history, and radiological findings is essential in establishing the diagnosis in others. In the presence of a history of exposure and consistent clinical features, the diagnosis of even an uncommon occupational lung disease can be suggested by the characteristic described HRCT findings. In this article, we briefly review the HRCT appearance of a wide spectrum of occupational lung diseases.

Spectrum of high-resolution computed tomography imaging in occupational lung disease

Directory of Open Access Journals (Sweden)

Bhawna Satija

2013-01-01

Full Text Available Damage to the lungs caused by dusts or fumes or noxious substances inhaled by workers in certain specific occupation is known as occupational lung disease. Recognition of occupational lung disease is especially important not only for the primary worker, but also because of the implications with regard to primary and secondary disease prevention in the exposed co-workers. Although many of the disorders can be detected on chest radiography, high-resolution computed tomography (HRCT is superior in delineating the lung architecture and depicting pathology. The characteristic radiological features suggest the correct diagnosis in some, whereas a combination of clinical features, occupational history, and radiological findings is essential in establishing the diagnosis in others. In the presence of a history of exposure and consistent clinical features, the diagnosis of even an uncommon occupational lung disease can be suggested by the characteristic described HRCT findings. In this article, we briefly review the HRCT appearance of a wide spectrum of occupational lung diseases.

Spectrum of high-resolution computed tomography imaging in occupational lung disease

International Nuclear Information System (INIS)

Satija, Bhawna; Kumar, Sanyal; Ojha, Umesh Chandra; Gothi, Dipti

2013-01-01

Damage to the lungs caused by dusts or fumes or noxious substances inhaled by workers in certain specific occupation is known as occupational lung disease. Recognition of occupational lung disease is especially important not only for the primary worker, but also because of the implications with regard to primary and secondary disease prevention in the exposed co-workers. Although many of the disorders can be detected on chest radiography, high-resolution computed tomography (HRCT) is superior in delineating the lung architecture and depicting pathology. The characteristic radiological features suggest the correct diagnosis in some, whereas a combination of clinical features, occupational history, and radiological findings is essential in establishing the diagnosis in others. In the presence of a history of exposure and consistent clinical features, the diagnosis of even an uncommon occupational lung disease can be suggested by the characteristic described HRCT findings. In this article, we briefly review the HRCT appearance of a wide spectrum of occupational lung diseases

Comparison between high-resolution computed tomography and 99mTc-technegas SPECT pulmonary emphysema

International Nuclear Information System (INIS)

Nakano, Satoru; Satoh, Katashi; Takahashi, Kazue

1996-01-01

Scintigraphy with 99m Tc-technegas was recently introduced for clinical imaging of lung ventilation. This method has been found to be useful in emergencies, to be more suitable for single photon emission computed tomography (SPECT) than other agents used in ventilation scintigraphy, and could reveal abnormalities in ventilation more easily than high resolution computed tomography (HRCT) in pulmonary emphysema. We compared 99m Tc-technegas SPECT with HRCT in six regions: the right upper, middle, and lower lobes, the left upper lobe, the lingula, and the left lower lobe, in 15 patients with pulmonary emphysema. Patients with centrilobular emphysema tended to show stronger changes in upper lobes than in lower lobes on both 99m Tc-technegas SPECT and HRCT. Some regions showed no change on HRCT but various changes on 99m Tc-SPECT. Patients with panlobular emphysema showed severe changes on 99m Tc-SPECT in lower lung fields in which well-demarcated areas of low attenuation were not seen on HRCT. We conclude that 99m Tc-SPECT is useful for detecting early changes and panlobular changes in pulmonary emphysema. (author)

High resolution propagation-based imaging system for in vivo dynamic computed tomography of lungs in small animals

Science.gov (United States)

Preissner, M.; Murrie, R. P.; Pinar, I.; Werdiger, F.; Carnibella, R. P.; Zosky, G. R.; Fouras, A.; Dubsky, S.

2018-04-01

We have developed an x-ray imaging system for in vivo four-dimensional computed tomography (4DCT) of small animals for pre-clinical lung investigations. Our customized laboratory facility is capable of high resolution in vivo imaging at high frame rates. Characterization using phantoms demonstrate a spatial resolution of slightly below 50 μm at imaging rates of 30 Hz, and the ability to quantify material density differences of at least 3%. We benchmark our system against existing small animal pre-clinical CT scanners using a quality factor that combines spatial resolution, image noise, dose and scan time. In vivo 4DCT images obtained on our system demonstrate resolution of important features such as blood vessels and small airways, of which the smallest discernible were measured as 55–60 μm in cross section. Quantitative analysis of the images demonstrate regional differences in ventilation between injured and healthy lungs.

Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation

International Nuclear Information System (INIS)

Santos, Maria Lucia de Oliveira; Vianna, Alberto Domingues; Marchiori, Edson; Souza Junior, Arthur Soares; Moraes, Heleno Pinto de

2003-01-01

Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its un specificity, association with other radiological, clinical and pathological findings must be considered for an accurate diagnostic interpretation. In this paper were reviewed 62 computed tomography examinations of patients with diffuse pulmonary diseases of 14 different etiologies in which ground-glass opacity was the only or the most remarkable finding, and correlated this findings with pathology abnormalities seen on specimens obtained from biopsies or necropsies. In pneumocystosis, ground-glass opacities correlated histologically with alveolar occupation by a foaming material containing parasites, in bronchiole alveolar cell carcinoma with thickening of the alveolar septa and occupation of the lumen by mucus and tumoral cells, in paracoccidioidomycosis with thickening of the alveolar septa, areas of fibrosis and alveolar bronchopneumonia exudate, in sarcoidosis with fibrosis or clustering of granulomas and in idiopathic pulmonary fibrosis with alveolar septa thickening due to fibrosis. Alveolar occupation by blood was found in cases of leptospirosis, idiopathic hemo siderosis, metastatic kidney tumor and invasive aspergillosis whereas oily vacuole were seen in lipoid pneumonia, proteinaceous and lipo proteinaceous material in silico proteinosis and pulmonary alveolar proteinosis, and edematous fluid in cardiac failure. (author)

High-resolution computed tomography findings in eight patients with hantavirus pulmonary syndrome

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Diego de Lacerda; Hochhegger, Bruno; Souza Junior, Arthur Soares; Zanetti, Glaucia; Escuissato, Dante Luiz; Meirelles, Gustavo de Souza Portes; Funari, Marcelo Buarque de Gusmao; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Santa Casa de Porto Alegre, Porto Alegre, RS (Brazil); Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil); Ultra X, Sao Jose do Rio Preto, SP (Brazil); Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil); Grupo Fleury, Sao Paulo, SP (Brazil); Universidade de Sao Paulo (FM/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina

2017-05-15

Objective: The purpose of this study was to describe the high-resolution computed tomography (HRCT) findings in patients with hantavirus pulmonary syndrome (HPS). Materials and Methods: We retrospectively reviewed HRCT findings from eight cases of HPS. All patients were men, aged 19-70 (mean, 41.7) years. Diagnoses were established by serological test (enzyme-linked immunosorbent assay) in all patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were ground-glass opacities (GGOs) and smooth inter- and intralobular septal thickening, found in all eight cases; however, the crazy-paving pattern was found in only three cases. Pleural effusion and peribronchovascular thickening were observed in five patients. The abnormalities were bilateral in all patients. Conclusion: The predominant HRCT findings in patients with HPS were GGOs and smooth inter- and intralobular septal thickening, which probably correlate with the histopathologic findings of pulmonary edema. (author)

High-resolution computed tomography findings in eight patients with hantavirus pulmonary syndrome

International Nuclear Information System (INIS)

Barbosa, Diego de Lacerda; Hochhegger, Bruno; Souza Junior, Arthur Soares; Zanetti, Glaucia; Escuissato, Dante Luiz; Meirelles, Gustavo de Souza Portes; Funari, Marcelo Buarque de Gusmao; Marchiori, Edson; Santa Casa de Porto Alegre, Porto Alegre, RS; Faculdade de Medicina de Sao Jose do Rio Preto; Ultra X, Sao Jose do Rio Preto, SP; Universidade Federal do Parana; Universidade Federal de Sao Paulo; Grupo Fleury, Sao Paulo, SP; Universidade de Sao Paulo

2017-01-01

Objective: The purpose of this study was to describe the high-resolution computed tomography (HRCT) findings in patients with hantavirus pulmonary syndrome (HPS). Materials and Methods: We retrospectively reviewed HRCT findings from eight cases of HPS. All patients were men, aged 19-70 (mean, 41.7) years. Diagnoses were established by serological test (enzyme-linked immunosorbent assay) in all patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were ground-glass opacities (GGOs) and smooth inter- and intralobular septal thickening, found in all eight cases; however, the crazy-paving pattern was found in only three cases. Pleural effusion and peribronchovascular thickening were observed in five patients. The abnormalities were bilateral in all patients. Conclusion: The predominant HRCT findings in patients with HPS were GGOs and smooth inter- and intralobular septal thickening, which probably correlate with the histopathologic findings of pulmonary edema. (author)

Halo sign nodules in angio invasive pulmonary aspergillosis: correlation of high-resolution computed tomography findings with anatomopathology; Nodulos com sinal do halo na aspergilose pulmonar angioinvasiva: 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; Valiante, Paulo Marcos [Universidade Federal, Rio de Janeiro, RJ (Brazil). Dept. de Patologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Disciplina de Radiologia

2002-08-01

The aim of this study was to correlate the early findings observed on high-resolution computed tomography with anatomopathology results of patients with angio invasive aspergillosis. The authors studied two patients with leukemia. The nodules seen on high-resolution computed tomography corresponded to areas of hemorrhagic infarction, necrotic coagulation and fungal hyphae infiltration whereas ground glass halo corresponded to intra alveolar hemorrhage. Nodules with halo sign were closely correlated with anatomopathology findings. We concluded that the anatomopathology findings can clearly explain the image features of the lesions observed on high-resolution computed tomography. (author)

Hypersensitivity pneumonitis (extrinsic allergic alveolitis): high-resolution computed tomography findings; Pneumonite por hipersensibilidade (alveolite alergica extrinseca): achados na tomografia computadorizada de alta resolucao

Energy Technology Data Exchange (ETDEWEB)

Almeida Junior, Jose Guiomar de; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Faculdade de Ciencias Medicas. Dept. de Radiologia]. E-mail: edmarchiori@zipmail.com.br; Escuissato, Dante L. [Parana Univ., Curitiba, PR (Brazil). Dept. de Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Radiologia; Gasparetto, Emerson L. [Parana Univ., Curitiba, PR (Brazil). Hospital de Clinicas; Nobre, Luiz Felipe [Santa Catarina Univ., Florianopolis, SC (Brazil); Irion, Klaus L. [Santa Casa de Misericordia de Porto Alegre, RS (Brazil). Pavilhao Pereira Filho. Servico de Radiologia

2003-12-01

Hypersensitivity pneumonitis, or extrinsic allergic alveolitis, is an immunologic disease of the lungs caused by inhaled chemicals or organics allergens. A lymphocytic inflammatory response in the peripheral airways and surrounding interstitial tissue occurs. In this study the high-resolution computed tomography findings of 13 patients with hypersensitivity pneumonitis were analyzed and discussed. The most frequent high-resolution computed tomography findings were: ground-glass opacities (92.3%), centrilobular nodules (38.4%) and air trapping (38.4%). Other findings included bronchiectasis (23.1%), consolidation (23.1%), crazy paving (7.7%), parenchymal bands (15.4%), linear opacities (7.7%), architectural distortion (7.7%), tracheal dilatation (7.7%), intralobular reticulate (7.7%), honeycombing (7.7%), emphysema (7.7%) and atelectasis (7.7%). In two of the 13 patients there was fibrosis (architectural distortion and honeycombing), which represents the chronic phase of the disease. (author)

High Resolution Computed Tomography in Asthma 

Directory of Open Access Journals (Sweden)

Nabil Maradny

2012-03-01

Full Text Available  Objectives: High-resolution computed tomography (HRCT can detect the structural abnormalities in asthma. This study attempts to correlate these abnormalities with clinical and pulmonary function test (PFT data.Methods: Consecutive stable asthma patients attending Mubarak Al Kabeer Hospital, Kuwait, were subjected to HRCT during a six month period from July 2004 to December 2004, after initial evaluation and PFT.Results: Of the 28 cases, sixteen (57.1�20had moderate, 6 (21.4�20had mild and 6 (21.4�20had severe persistent asthma. Thirteen (46.4�20patients had asthma for 1 to 5 years and 12 (42.9�20were having asthma for >10 years. Bronchial wall thickening (57.1� bronchiectasis (28.6� mucoid impaction (17.9� mosaic attenuation (10.7� air trapping (78.6�20and plate like atelectasis (21.4�20were noted. Bronchial wall thickening (p=0.044 and bronchiectasis (p=0.063 were most prevalent in males. Ten (35.7�20patients exhibited mild, 9 (32.1�20had moderate and 3 (10.7�20had severe air trapping. The difference in Hounsfield units between expiratory and inspiratory slices (air trapping when correlated with percent-predicted FEV1 in right upper (r=0.25;p=0.30, left upper (r=0.20; p=0.41, right mid (r=0.15; p=0.53, left mid (r=-0.04; p=0.60, right lower (r=0.04; p=0.86 and left lower zones (r=-0.13; p=0.58 showed no relation. The same when correlated as above with the percent predicted FEF 25-75 did not show any significant association. The presence of air trapping was compared with sex (p=0.640, nationality (p=1.000, disease duration (p=1.000 and severity of symptoms (p=0.581.Conclusion: Abnormal HRCT findings are common in asthma; however, air trapping when present was not related to the duration or severity of the illness or to the FEV1.

Pneumocystis carinii pneumonia in acquired immunodeficiency syndrome - correlation of high-resolution computed tomography and anatomopathology; Pneumocistose na sindrome da imunodeficiencia adquirida: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

Energy Technology Data Exchange (ETDEWEB)

Marchiori, Edson; Moreira, Luiza Beatriz [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@zipmail.com.br; Capone, Domenico [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina; Moraes, Heleno Pinto de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Patologia; Pereira, Cyntia Inez Guedes Soares

2001-12-01

We present the main findings observed on the high-resolution computed tomography examinations of 15 patients with acquired immunodeficiency syndrome and Pneumocystis carinii pneumonia. The high-resolution computed tomography and autopsy findings of 5 patients were also compared. The most frequently observed high-resolution computed tomography patterns were ground-glass attenuation, consolidation areas, crazy-paving pattern and cysts. Nodules and intralobular reticulation were less frequently observed. Ground-glass attenuation and consolidation areas corresponded to alveolar filling with inflammatory exudate. Thickening of the interlobular septa was due to cell infiltration and edema. One patient presented interlobular reticulation, and the pathology study revealed alveolar septa thickening due to cell infiltration and fibrosis. Nodules observed in one of the patients corresponded to a patchy intra alveolar accumulation of microorganisms and inflammatory cells forming a 'granulomatous' pattern. (author)

Pulmonary high-resolution computed tomography findings in nephropathia epidemica

Energy Technology Data Exchange (ETDEWEB)

Paakkala, Antti, E-mail: antti.paakkala@pshp.fi [Medical Imaging Centre, Tampere University Hospital, 33521 Tampere (Finland); Jaervenpaeae, Ritva, E-mail: ritva.jarvenpaa@pshp.fi [Medical Imaging Centre, Tampere University Hospital, 33521 Tampere (Finland); Maekelae, Satu, E-mail: satu.marjo.makela@uta.fi [Department of Internal Medicine, Tampere University Hospital, 33521 Tampere (Finland); Medical School, University of Tampere, 33521 Tampere (Finland); Huhtala, Heini, E-mail: heini.huhtala@uta.fi [School of Public Health, University of Tampere, 33521 Tampere (Finland); Mustonen, Jukka, E-mail: jukka.mustonen@uta.fi [Department of Internal Medicine, Tampere University Hospital, 33521 Tampere (Finland); Medical School, University of Tampere, 33521 Tampere (Finland)

2012-08-15

Purpose: To evaluate lung high-resolution computed tomography (HRCT) findings in patients with Puumala hantavirus-induced nephropathia epidemica (NE), and to determine if these findings correspond to chest radiograph findings. Materials and methods: HRCT findings and clinical course were studied in 13 hospital-treated NE patients. Chest radiograph findings were studied in 12 of them. Results: Twelve patients (92%) showed lung parenchymal abnormalities in HRCT, while only 8 had changes in their chest radiography. Atelectasis, pleural effusion, intralobular and interlobular septal thickening were the most common HRCT findings. Ground-glass opacification (GGO) was seen in 4 and hilar and mediastinal lymphadenopathy in 3 patients. Atelectasis and pleural effusion were also mostly seen in chest radiographs, other findings only in HRCT. Conclusion: Almost every NE patient showed lung parenchymal abnormalities in HRCT. The most common findings of lung involvement in NE can be defined as accumulation of pleural fluid and atelectasis and intralobular and interlobular septal thickening, most profusely in the lower parts of the lung. As a novel finding, lymphadenopathy was seen in a minority, probably related to capillary leakage and overall fluid overload. Pleural effusion is not the prominent feature in other viral pneumonias, whereas intralobular and interlobular septal thickening are characteristic of other viral pulmonary infections as well. Lung parenchymal findings in HRCT can thus be taken not to be disease-specific in NE and HRCT is useful only for scientific purposes.

Applications of X-ray Computed Tomography and Emission Computed Tomography

International Nuclear Information System (INIS)

Seletchi, Emilia Dana; Sutac, Victor

2005-01-01

Computed Tomography is a non-destructive imaging method that allows visualization of internal features within non-transparent objects such as sedimentary rocks. Filtering techniques have been applied to circumvent the artifacts and achieve high-quality images for quantitative analysis. High-resolution X-ray computed tomography (HRXCT) can be used to identify the position of the growth axis in speleothems by detecting subtle changes in calcite density between growth bands. HRXCT imagery reveals the three-dimensional variability of coral banding providing information on coral growth and climate over the past several centuries. The Nuclear Medicine imaging technique uses a radioactive tracer, several radiation detectors, and sophisticated computer technologies to understand the biochemical basis of normal and abnormal functions within the brain. The goal of Emission Computed Tomography (ECT) is to accurately determine the three-dimensional radioactivity distribution resulting from the radiopharmaceutical uptake inside the patient instead of the attenuation coefficient distribution from different tissues as obtained from X-ray Computer Tomography. ECT is a very useful tool for investigating the cognitive functions. Because of the low radiation doses associated with Positron Emission Tomography (PET), this technique has been applied in clinical research, allowing the direct study of human neurological diseases. (authors)

Imaging of cellular spread on a three-dimensional scaffold by means of a novel cell-labeling technique for high-resolution computed tomography

NARCIS (Netherlands)

Thimm, B.W.; Hofmann, S.; Schneider, P.; Carretta, R.; Müller, R.

2012-01-01

Computed tomography (CT) represents a truly three-dimensional (3D) imaging technique that can provide high-resolution images on the cellular level. Thus, one approach to detect single cells is X-ray absorption-based CT, where cells are labeled with a dense, opaque material providing the required

High-resolution computed tomography findings in pulmonary complications after bone marrow transplantation: iconographic essay

International Nuclear Information System (INIS)

Gasparetto, Emerson L.; Ono, Sergio E.; Souza, Carolina A.; Escuissato, Dante L.; Rocha, Gabriela de Melo; Inoue, Cezar; Falavigna, Joao M.; Marchiori, Edson; Universidade Federal, Rio de Janeiro

2005-01-01

Bone marrow transplantation has been the treatment of choice for many hematologic diseases. However, pulmonary complications, which may occur in up to 60% of the patients, are the main cause of treatment failure and may be divided in three phases according to the patient's immunity. In the first phase, up to 30 days after the procedure, there is a predominance of non-infectious complications and fungal pneumonia. Viral infections, mainly by cytomegalovirus, are common in the second phase (up to 100 days after bone marrow transplantation). Finally, in the late phase after bone marrow transplantation, non-infectious complications as bronchiolitis obliterans organizing pneumonia and graft-versus-host disease are most commonly seen. The authors present a pictorial essay of the high-resolution computed tomography findings in patients with pulmonary complications after bone marrow transplantation. (author)

Paracoccidioidomycosis: high-resolution computed tomography - anatomo-pathological correlation; Paracoccidioidomicose: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

Energy Technology Data Exchange (ETDEWEB)

Marchiori, Edson; Muniz, Maria Angelica Soares; Santos, Maria Lucia de Oliveira [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Radiologia; Moraes, Heleno Pinto de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Patologia; Capone, Domenico [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Pneumologia

2000-12-01

We reviewed the high-resolution computed tomography scans of 13 patients with paracoccidioidomycosis and correlated the findings with the anatomo-pathological findings of 5 patients. The most frequent findings observed were thickening of the interlobular septa, emphysema, ground glass areas, thickening of bronchial walls, tracheal dilatation, nodules, cavities and evidence of fibrosing disease such as architectural distortion, parenchymatous bands, spicular pleural thickening, intralobular reticulate and thickening with distortion off the axial interstitium. (author)

Clinical cone beam computed tomography compared to high-resolution peripheral computed tomography in the assessment of distal radius bone.

Science.gov (United States)

de Charry, C; Boutroy, S; Ellouz, R; Duboeuf, F; Chapurlat, R; Follet, H; Pialat, J B

2016-10-01

Clinical cone beam computed tomography (CBCT) was compared to high-resolution peripheral quantitative computed tomography (HR-pQCT) for the assessment of ex vivo radii. Strong correlations were found for geometry, volumetric density, and trabecular structure. Using CBCT, bone architecture assessment was feasible but compared to HR-pQCT, trabecular parameters were overestimated whereas cortical ones were underestimated. HR-pQCT is the most widely used technique to assess bone microarchitecture in vivo. Yet, this technology has been only applicable at peripheral sites, in only few research centers. Clinical CBCT is more widely available but quantitative assessment of the bone structure is usually not performed. We aimed to compare the assessment of bone structure with CBCT (NewTom 5G, QR, Verona, Italy) and HR-pQCT (XtremeCT, Scanco Medical AG, Brüttisellen, Switzerland). Twenty-four distal radius specimens were scanned with these two devices with a reconstructed voxel size of 75 μm for Newtom 5G and 82 μm for XtremeCT, respectively. A rescaling-registration scheme was used to define the common volume of interest. Cortical and trabecular compartments were separated using a semiautomated double contouring method. Density and microstructure were assessed with the HR-pQCT software on both modality images. Strong correlations were found for geometry parameters (r = 0.98-0.99), volumetric density (r = 0.91-0.99), and trabecular structure (r = 0.94-0.99), all p < 0.001. Correlations were lower for cortical microstructure (r = 0.80-0.89), p < 0.001. However, absolute differences were observed between modalities for all parameters, with an overestimation of the trabecular structure (trabecular number, 1.62 ± 0.37 vs. 1.47 ± 0.36 mm(-1)) and an underestimation of the cortical microstructure (cortical porosity, 3.3 ± 1.3 vs. 4.4 ± 1.4 %) assessed on CBCT images compared to HR-pQCT images. Clinical CBCT devices are able to

Pulmonary malaria: high-resolution computed tomography findings - a case report; Malaria pulmonar: aspectos na tomografia computadorizada de alta resolucao - relato de caso

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Rosana; Souza, Daniel Andrade Tinoco de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Hospital Universitario Clementino Fraga Filho. Servico de Radiodiagnostico; Hospital Copa D' Or, Rio de Janeiro, RJ (Brazil); Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@bol.com.br

2004-04-01

We report the case of a 38-year-old man with pulmonary malaria. High-resolution computed tomography showed thickening of the peribronchovascular interstitium and interlobular septa, areas of consolidation and ground glass attenuation and bilateral pleural effusion suggesting pulmonary edema. The patient recovered well after receiving specific treatment and was discharged after 11 days of hospitalization. (author)

Using high resolution X-ray computed tomography to create an image based model of a lymph node.

Science.gov (United States)

Cooper, L J; Zeller-Plumhoff, B; Clough, G F; Ganapathisubramani, B; Roose, T

2018-07-14

Lymph nodes are an important part of the immune system. They filter the lymphatic fluid as it is transported from the tissues before being returned to the blood stream. The fluid flow through the nodes influences the behaviour of the immune cells that gather within the nodes and the structure of the node itself. Measuring the fluid flow in lymph nodes experimentally is challenging due to their small size and fragility. In this paper, we present high resolution X-ray computed tomography images of a murine lymph node. The impact of the resulting visualized structures on fluid transport are investigated using an image based model. The high contrast between different structures within the lymph node provided by phase contrast X-ray computed tomography reconstruction results in images that, when related to the permeability of the lymph node tissue, suggest an increased fluid velocity through the interstitial channels in the lymph node tissue. Fluid taking a direct path from the afferent to the efferent lymphatic vessel, through the centre of the node, moved faster than the fluid that flowed around the periphery of the lymph node. This is a possible mechanism for particles being moved into the cortex. Copyright © 2018 Elsevier Ltd. All rights reserved.

Attenuation Correction Strategies for Positron Emission Tomography/Computed Tomography and 4-Dimensional Positron Emission Tomography/Computed Tomography

OpenAIRE

Pan, Tinsu; Zaidi, Habib

2013-01-01

This article discusses attenuation correction strategies in positron emission tomography/computed tomography (PET/CT) and 4 dimensional PET/CT imaging. Average CT scan derived from averaging the high temporal resolution CT images is effective in improving the registration of the CT and the PET images and quantification of the PET data. It underscores list mode data acquisition in 4 dimensional PET and introduces 4 dimensional CT popular in thoracic treatment planning to 4 dimensional PET/CT. ...

Metastatic pulmonary calcification: high-resolution computed tomography findings in 23 cases

Directory of Open Access Journals (Sweden)

Luciana Camara Belém

Full Text Available Abstract Objective: The aim of this study was to evaluate the high-resolution computed tomography (HRCT findings in patients diagnosed with metastatic pulmonary calcification (MPC. Materials and Methods: We retrospectively reviewed the HRCT findings from 23 cases of MPC [14 men, 9 women; mean age, 54.3 (range, 26-89 years]. The patients were examined between 2000 and 2014 in nine tertiary hospitals in Brazil, Chile, and Canada. Diagnoses were established by histopathologic study in 18 patients and clinical-radiological correlation in 5 patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were centrilobular ground-glass nodules (n = 14; 60.9%, consolidation with high attenuation (n = 10; 43.5%, small dense nodules (n = 9; 39.1%, peripheral reticular opacities associated with small calcified nodules (n = 5; 21.7%, and ground-glass opacities without centrilobular ground-glass nodular opacity (n = 5; 21.7%. Vascular calcification within the chest wall was found in four cases and pleural effusion was observed in five cases. The abnormalities were bilateral in 21 cases. Conclusion: MPC manifested with three main patterns on HRCT, most commonly centrilobular ground-glass nodules, often containing calcifications, followed by dense consolidation and small solid nodules, most of which were calcified. We also described another pattern of peripheral reticular opacities associated with small calcified nodules. These findings should suggest the diagnosis of MPC in the setting of hypercalcemia.

Metastatic pulmonary calcification: high-resolution computed tomography findings in 23 cases

Energy Technology Data Exchange (ETDEWEB)

Belem, Luciana Camara; Souza, Carolina A.; Souza Junior, Arthur Soares; Escuissato, Dante Luiz; Hochhegger, Bruno; Nobre, Luiz Felipe; Rodrigues, Rosana Souza; Gomes, Antonio Carlos Portugal; Silva, Claudio S.; Guimaraes, Marcos Duarte; Zanetti, Glaucia; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Ottawa Hospital Research Institute, University of Ottawa, (Canada); Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil); Ultra X, Sao Jose do Rio Preto, SP (Brazil); Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil); Universidade Federal de Ciencias da Saude de Porto Alegre (UFCSPA), Porto Alegre, RS (Brazil); Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Hospital Universitario

2017-07-15

Objective: The aim of this study was to evaluate the high-resolution computed tomography (HRCT) findings in patients diagnosed with metastatic pulmonary calcification (MPC). Materials and Methods: We retrospectively reviewed the HRCT findings from 23 cases of MPC [14 men, 9 women; mean age, 54.3 (range, 26-89) years]. The patients were examined between 2000 and 2014 in nine tertiary hospitals in Brazil, Chile, and Canada. Diagnoses were established by histopathologic study in 18 patients and clinical-radiological correlation in 5 patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were centrilobular ground-glass nodules (n = 14; 60.9%), consolidation with high attenuation (n = 10; 43.5%), small dense nodules (n = 9; 39.1%), peripheral reticular opacities associated with small calcified nodules (n = 5; 21.7%), and ground-glass opacities without centrilobular ground-glass nodular opacity (n = 5; 21.7%). Vascular calcification within the chest wall was found in four cases and pleural effusion was observed in five cases. The abnormalities were bilateral in 21 cases. Conclusion: MPC manifested with three main patterns on HRCT, most commonly centrilobular ground-glass nodules, often containing calcifications, followed by dense consolidation and small solid nodules, most of which were calcified. We also described another pattern of peripheral reticular opacities associated with small calcified nodules. These findings should suggest the diagnosis of MPC in the setting of hypercalcemia. (author)

Metastatic pulmonary calcification: high-resolution computed tomography findings in 23 cases

International Nuclear Information System (INIS)

Belem, Luciana Camara; Souza, Carolina A.; Souza Junior, Arthur Soares; Escuissato, Dante Luiz; Hochhegger, Bruno; Nobre, Luiz Felipe; Rodrigues, Rosana Souza; Gomes, Antonio Carlos Portugal; Silva, Claudio S.; Guimaraes, Marcos Duarte; Zanetti, Glaucia; Marchiori, Edson; Ottawa Hospital Research Institute, University of Ottawa,; Faculdade de Medicina de Sao Jose do Rio Preto; Ultra X, Sao Jose do Rio Preto, SP; Universidade Federal do Parana; Universidade Federal de Ciencias da Saude de Porto Alegre; Universidade Federal de Santa Catarina

2017-01-01

Objective: The aim of this study was to evaluate the high-resolution computed tomography (HRCT) findings in patients diagnosed with metastatic pulmonary calcification (MPC). Materials and Methods: We retrospectively reviewed the HRCT findings from 23 cases of MPC [14 men, 9 women; mean age, 54.3 (range, 26-89) years]. The patients were examined between 2000 and 2014 in nine tertiary hospitals in Brazil, Chile, and Canada. Diagnoses were established by histopathologic study in 18 patients and clinical-radiological correlation in 5 patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were centrilobular ground-glass nodules (n = 14; 60.9%), consolidation with high attenuation (n = 10; 43.5%), small dense nodules (n = 9; 39.1%), peripheral reticular opacities associated with small calcified nodules (n = 5; 21.7%), and ground-glass opacities without centrilobular ground-glass nodular opacity (n = 5; 21.7%). Vascular calcification within the chest wall was found in four cases and pleural effusion was observed in five cases. The abnormalities were bilateral in 21 cases. Conclusion: MPC manifested with three main patterns on HRCT, most commonly centrilobular ground-glass nodules, often containing calcifications, followed by dense consolidation and small solid nodules, most of which were calcified. We also described another pattern of peripheral reticular opacities associated with small calcified nodules. These findings should suggest the diagnosis of MPC in the setting of hypercalcemia. (author)

High-resolution computed tomography findings in chronic eosinophilic vs. cryptogenic organising pneumonia.

Science.gov (United States)

Mehrian, P; Doroudinia, A; Rashti, A; Aloosh, O; Dorudinia, A

2017-11-01

The similar clinical and computed tomography (CT) characteristics of cryptogenic organising pneumonia (COP) and chronic eosinophilic pneumonia (CEP) make precise diagnosis challenging. To help differentiate between COP and CEP using high-resolution CT (HRCT). Clinical data and HRCT images of COP and CEP patients referred to Masih Daneshvari Hospital, Tehran, Iran, from 2007 to 2015 were reviewed. Diagnosis of COP or CEP was confirmed using open lung biopsy or a combination of transbronchial biopsy, bronchoalveolar lavage fluid (BALF) analysis, peripheral eosinophilia and a favourable response to corticosteroids. Ground-glass opacity, a dominant ground-glass pattern, upper-lobe pneumonia, increased thickness of bronchial walls and a mosaic pattern in the lungs were more frequent in CEP. Lower-lobe pneumonia, subpleural reticulation, a dominant consolidation pattern, nodules and masses, non-septal linear opacities, bronchial dilation and a reverse halo sign were more frequent in COP. History of asthma, wheezing and peripheral eosinophilia was significantly more common in CEP than in COP. Distinguishing between CEP and COP based on HRCT alone is not always possible. However, in many cases, especially if the correct diagnosis cannot be established by other means, certain HRCT features can be very helpful.

High resolution positron tomography

International Nuclear Information System (INIS)

Brownell, G.L.; Burnham, C.A.

1982-01-01

The limits of spatial resolution in practical positron tomography are examined. The four factors that limit spatial resolution are: positron range; small angle deviation; detector dimensions and properties; statistics. Of these factors, positron range may be considered the fundamental physical limitation since it is independent of instrument properties. The other factors are to a greater or lesser extent dependent on the design of the tomograph

Three-dimensional reconstruction and modeling of middle ear biomechanics by high-resolution computed tomography and finite element analysis.

Science.gov (United States)

Lee, Chia-Fone; Chen, Peir-Rong; Lee, Wen-Jeng; Chen, Jyh-Horng; Liu, Tien-Chen

2006-05-01

To present a systematic and practical approach that uses high-resolution computed tomography to derive models of the middle ear for finite element analysis. This prospective study included 31 subjects with normal hearing and no previous otologic disorders. Temporal bone images obtained from 15 right ears and 16 left ears were used for evaluation and reconstruction. High-resolution computed tomography of temporal bone was performed using simultaneous acquisition of 16 sections with a collimated slice thickness of 0.625 mm. All images were transferred to an Amira visualization system for three-dimensional reconstruction. The created three-dimensional model was translated into two commercial modeling packages, Patran and ANSYS, for finite element analysis. The characteristic dimensions of the model were measured and compared with previously published histologic section data. This result confirms that the geometric model created by the proposed method is accurate except that the tympanic membrane is thicker than when measured by the histologic section method. No obvious difference in the geometrical dimension between right and left ossicles was found (P > .05). The three-dimensional model created by finite element method and predicted umbo and stapes displacements are close to the bounds of the experimental curves of Nishihara's, Huber's, Gan's, and Sun's data across the frequency range of 100 to 8000 Hz. The model includes a description of the geometry of the middle ear components and dynamic equations of vibration. The proposed method is quick, practical, low-cost, and, most importantly, noninvasive as compared with histologic section methods.

Second Mesiobuccal Root Canal of Maxillary First Molars in a Brazilian Population in High-Resolution Cone-Beam Computed Tomography.

Science.gov (United States)

Gomes Alves, Claudia Rezende; Martins Marques, Márcia; Stella Moreira, Maria; Harumi Miyagi de Cara, Sueli Patricia; Silveira Bueno, Carlos Eduardo; Lascala, Cesar Ângelo

2018-01-01

The second canal of the mesiobuccal root (MB2) of the maxillary first molars (MFM) is difficult to detect in conventional radiographs and can be a major cause of failure in endodontic treatments. The aim of this study was to investigate the prevalence and anatomy of the MB2 by using high-resolution cone-beam computed tomography (CBCT). Three radiologists examined 414 high-resolution CBCTs. Of these, the CBCTs of 287 patients (mean age 49.43±16.76) who had at least one MFM were selected, making a total of 362 teeth. Prevalence and its relation with gender and age of the patients, side of the tooth, and Vertucci's classification were analyzed. Data were statistically analyzed ( P molars in this Brazilian population examined with high-resolution CBTCs is 68.23%, being more prevalent in young patients. Gender and the side examined are no factors for determining the presence of MB2. Although the both FOVs of the high-resolution CBTCs (FOV 8 and 5) detect the MB2 canal, smaller FOV (FOV 5) is more accurate in the analysis of the internal anatomy of such root canals, according to the Vertucci´s classification.

High-resolution-cone beam tomography analysis of bone microarchitecture in patients with acromegaly and radiological vertebral fractures.

Science.gov (United States)

Maffezzoni, Filippo; Maddalo, Michele; Frara, Stefano; Mezzone, Monica; Zorza, Ivan; Baruffaldi, Fabio; Doglietto, Francesco; Mazziotti, Gherardo; Maroldi, Roberto; Giustina, Andrea

2016-11-01

Vertebral fractures are an emerging complication of acromegaly but their prediction is still difficult occurring even in patients with normal bone mineral density. In this study we evaluated the ability of high-resolution cone-beam computed tomography to provide information on skeletal abnormalities associated with vertebral fractures in acromegaly. 40 patients (24 females, 16 males; median age 57 years, range 25-72) and 21 healthy volunteers (10 females, 11 males; median age 60 years, range: 25-68) were evaluated for trabecular (bone volume/trabecular volume ratio, mean trabecular separation, and mean trabecular thickness) and cortical (thickness and porosity) parameters at distal radius using a high-resolution cone-beam computed tomography system. All acromegaly patients were evaluated for morphometric vertebral fractures and for mineral bone density by dual-energy X-ray absorptiometry at lumbar spine, total hip, femoral neck, and distal radius. Acromegaly patients with vertebral fractures (15 cases) had significantly (p acromegaly patients did not have significant differences in bone density at either skeletal site. Patients with acromegaly showed lower bone volume/trabecular volume ratio (p = 0.003) and mean trabecular thickness (p acromegaly. High-resolution cone-beam computed tomography at the distal radius may be useful to evaluate and predict the effects of acromegaly on bone microstructure.

TH-AB-209-07: High Resolution X-Ray-Induced Acoustic Computed Tomography

Energy Technology Data Exchange (ETDEWEB)

Xiang, L; Tang, S [University of Oklahoma, Norman, OK (United States); Ahmad, M [Stanford University, Palo Alto, CA (United States); Xing, L [Stanford University School of Medicine, Stanford, CA (United States)

2016-06-15

Purpose: X-ray radiographic absorption imaging is an invaluable tool in medical diagnostics, biology and materials science. However, the use of conventional CT is limited by two factors: the detection sensitivity to weak absorption material and the radiation dose from CT scanning. The purpose of this study is to explore X-ray induced acoustic computed tomography (XACT), a new imaging modality, which combines X-ray absorption contrast and high ultrasonic resolution to address these challenges. Methods: First, theoretical models was built to analyze the XACT sensitivity to X-ray absorption and calculate the minimal radiation dose in XACT imaging. Then, an XACT system comprised of an ultrashort X-ray pulse, a low noise ultrasound detector and a signal acquisition system was built to evaluate the X-ray induced acoustic signal generation. A piece of chicken bone and a phantom with two golden fiducial markers were exposed to 270 kVp X-ray source with 60 ns exposure time, and the X-ray induced acoustic signal was received by a 2.25MHz ultrasound transducer in 200 positions. XACT images were reconstructed by a filtered back-projection algorithm. Results: The theoretical analysis shows that X-ray induced acoustic signals have 100% relative sensitivity to X-ray absorption, but not to X-ray scattering. Applying this innovative technology to breast imaging, we can reduce radiation dose by a factor of 50 compared with newly FDA approved breast CT. The reconstructed images of chicken bone and golden fiducial marker phantom reveal that the spatial resolution of the built XACT system is 350µm. Conclusion: In XACT, the imaging sensitivity to X-ray absorption is improved and the imaging dose is dramatically reduced by using ultrashort pulsed X-ray. Taking advantage of the high ultrasonic resolution, we can also perform 3D imaging with a single X-ray pulse. This new modality has the potential to revolutionize x-ray imaging applications in medicine and biology.

Early-state damage detection, characterization, and evolution using high-resolution computed tomography

Science.gov (United States)

Grandin, Robert John

Safely using materials in high performance applications requires adequately understanding the mechanisms which control the nucleation and evolution of damage. Most of a material's operational life is spent in a state with noncritical damage, and, for example in metals only a small portion of its life falls within the classical Paris Law regime of crack growth. Developing proper structural health and prognosis models requires understanding the behavior of damage in these early stages within the material's life, and this early-stage damage occurs on length scales at which the material may be considered "granular'' in the sense that the discrete regions which comprise the whole are large enough to require special consideration. Material performance depends upon the characteristics of the granules themselves as well as the interfaces between granules. As a result, properly studying early-stage damage in complex, granular materials requires a means to characterize changes in the granules and interfaces. The granular-scale can range from tenths of microns in ceramics, to single microns in fiber-reinforced composites, to tens of millimeters in concrete. The difficulty of direct-study is often overcome by exhaustive testing of macro-scale damage caused by gross material loads and abuse. Such testing, for example optical or electron microscopy, destructive and further, is costly when used to study the evolution of damage within a material and often limits the study to a few snapshots. New developments in high-resolution computed tomography (HRCT) provide the necessary spatial resolution to directly image the granule length-scale of many materials. Successful application of HRCT with fiber-reinforced composites, however, requires extending the HRCT performance beyond current limits. This dissertation will discuss improvements made in the field of CT reconstruction which enable resolutions to be pushed to the point of being able to image the fiber-scale damage structures and

High resolution X-ray tomography for stationary multiphase flows

International Nuclear Information System (INIS)

Schmitz, D.; Reinecke, N.; Petritsch, G.; Mewes, D.

1998-01-01

The high resolution which can be obtained by computer assisted tomography is used to investigate the liquid distribution and void fraction in random and structured packing. With a spatial resolution of 0.4x0.4mm 2 it is possible even to detect thin liquid films on structured packings. The experimental set-up consists of a custom-built second generation tomograph. The imaged object consists of a column filled with either a random ceramic packing of spheres or a structured metal packing. The liquid and void fraction distribution in random and structured packings with a quiescent gaseous phase is visualized. The water/air system is used. The liquid distributor consists of a perforated plate. The experimental hold-up values averaged over the column cross-section are in good agreement with empirical equations. (author)

Effects of polytetrafluoroethylene treatment and compression on gas diffusion layer microstructure using high-resolution X-ray computed tomography

Science.gov (United States)

Khajeh-Hosseini-Dalasm, Navvab; Sasabe, Takashi; Tokumasu, Takashi; Pasaogullari, Ugur

2014-11-01

The microstructure of a TGP-H-120 Toray paper gas diffusion layer (GDL) was investigated using high resolution X-ray computed tomography (CT) technique, with a resolution of 1.8 μm and a field of view (FOV) of ∼1.8 × 1.8 mm. The images obtained from the tomography scans were further post processed, and image thresholding and binarization methodologies are presented. The validity of Otsu's thresholding method was examined. Detailed information on bulk porosity and porosity distribution of the GDL at various Polytetrafluoroethylene (PTFE) treatments and uniform/non-uniform compression pressures was provided. A sample holder was designed to investigate the effects of non-uniform compression pressure, which enabled regulating compression pressure between 0, and 3 MPa at a gas channel/current collector rib configuration. The results show the heterogeneous and anisotropic microstructure of the GDL, non-uniform distribution of PTFE, and significant microstructural change under uniform/non-uniform compression. These findings provide useful inputs for numerical models to include the effects of microstructural changes in the study of transport phenomena within the GDL and to increase the accuracy and predictability of cell performance.

Aspects of pulmonary histiocytosis X on high resolution computed tomography; Aspectos da histiocitose X pulmonar na tomografia computadorizada de alta resolucao (TCAR)

Energy Technology Data Exchange (ETDEWEB)

Costa, N.S.S.; Castro Lessa Angela, M.T. de; Angelo Junior, J.R.L.; Silva, F.M.D.; Kavakama, J.; Carvalho, C.R.R. de; Cerri, G.G. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Hospital das Clinicas. Inst. do Coracao

1995-01-01

Pulmonary histiocytosis X is a disease that occurs in young adults and presents with nodules and cysts, mainly in upper lobes, with consequent pulmonary fibrosis. These pulmonary changes are virtually pathognomonic findings on high resolution computed tomography, that allows estimate the area of the lung involved and distinguish histiocytosis X from other disorders that also produces nodules and cysts. (author). 10 refs, 2 tabs, 6 figs.

Refinement procedure for the image alignment in high-resolution electron tomography

International Nuclear Information System (INIS)

Houben, L.; Bar Sadan, M.

2011-01-01

High-resolution electron tomography from a tilt series of transmission electron microscopy images requires an accurate image alignment procedure in order to maximise the resolution of the tomogram. This is the case in particular for ultra-high resolution where even very small misalignments between individual images can dramatically reduce the fidelity of the resultant reconstruction. A tomographic-reconstruction based and marker-free method is proposed, which uses an iterative optimisation of the tomogram resolution. The method utilises a search algorithm that maximises the contrast in tomogram sub-volumes. Unlike conventional cross-correlation analysis it provides the required correlation over a large tilt angle separation and guarantees a consistent alignment of images for the full range of object tilt angles. An assessment based on experimental reconstructions shows that the marker-free procedure is competitive to the reference of marker-based procedures at lower resolution and yields sub-pixel accuracy even for simulated high-resolution data. -- Highlights: → Alignment procedure for electron tomography based on iterative tomogram contrast optimisation. → Marker-free, independent of object, little user interaction. → Accuracy competitive with fiducial marker methods and suited for high-resolution tomography.

The high-grade interpolator: a means for enhancing the resolution of helical computed tomography images of the lung

International Nuclear Information System (INIS)

Garcia-Santos, J. M.; Torres del rio, S.; Blanco, A.; Rodriguez, R.; Parlorio, E.; Garcia, A.; Girela, E.; Hernandez, M. D.; Canteras, M.

2002-01-01

The purpose of this study was to demonstrate that the use of a high-grade interpolator in the reconstruction of images of the chest increases the resolution, independently of the high-resolution filter. Eight independent observers in two groups (experts and non experts) assessed (two readings separated by a time interval) the same section of the chest reconstructed four times (st-st, st-xs, b-st, b-xs), combining standard (st) and high-resolution (b) filters and standard (st) and high-grade (xs) interpolators. The images were classified from greater to lesser in terms of the resolution perceived. The results were used to compare the degree of resolution introduced by the interpolator and the filter and to determine whether or not there existed variability between observers and between the observations of each, and whether experience played a role in the findings. Six of the eight observers assigned the b-xs images the highest degree of resolution in the majority of cases, followed by the b-st image, the st-xs image and, finally, the st-st image). The other tow observers (one expert and one nonexpert) different only with respect to the order of the st-xs and b-st images, which they assigned the second and third places, respectively. The expert group showed no intra observer variability, while two of the nonexpert observers did. The high-grade interpolator enhances the resolution of images of the chest regardless of who evaluates them, while it does not substantially increase image noise. Thus, its use is recommended in helical computed tomography imaging of the lung. (Author) 10 refs

New detector developments for high resolution positron emission tomography

International Nuclear Information System (INIS)

Ziegler, S.I.; Pichler, B.; Lorenz, E.

1998-01-01

The strength of quantitative, functional imaging using positron emission tomography, specially in small animals, is limited due to the spatial resolution. Therefore, various tomograph designs employing new scintillators, light sensors, or coincidence electronic are investigated to improve resolution without losses in sensitivity. Luminous scintillators with short light decay time in combination with novel readout schemes using photomultipliers or semiconductor detectors are currently tested by several groups and are implemented in tomographs for small animals. This review summarises the state of development in high resolution positron emission tomography with a detailed description of a system incorporating avalanche photodiode arrays and small scintillation crystals. (orig.) [de

High-resolution computed tomography findings in elderly patients with asthma

International Nuclear Information System (INIS)

Yilmaz, Sevda; Ekici, Aydanur; Ekici, Mehmet; Keles, Hatice

2006-01-01

Objective: Based on the hypothesis that airway remodelling is related to the duration of asthma, HRCT scanning should show greater abnormalities in the early-onset than the late-onset asthmatics. It was, therefore, intended to assess the presence and the frequency of airway and parenchymal abnormalities with high-resolution computed tomography (HRCT) in elderly asthmatic patients, and to determine whether these abnormalities are related to the duration of asthma. Patients and methods: Sixty-eight clinically stable asthmatic patients aged ≥60 yr were included in this prospective study. The patients were separated into two groups according to the duration of symptoms as late-onset asthma (n = 31) with disease duration of <5 yr, and early-onset asthma (n = 37) with disease duration of ≥5 yr. All patients were lifelong non-smoker and had been using inhaled beta agonists and inhaled steroids. HRCT-scanning and histamine inhalation test were performed on all patients. Results: In comparison with late-onset asthmatic patients, those with early-onset asthma had significantly higher frequency of emphysema (21.6% versus 0.0%, p = 0.006), bronchial dilatation (13.9% versus 0.0%, p 0.03) and bronchial wall thickness (41.7% versus 12.9%, p = 0.01). Multiple logistic regression analysis identified that early-onset of disease was an independent risk factor for the presence of irreversible HRCT-scan abnormalities in elderly asthmatics [odds ratio (OR): 9.4 (2.7-32.7), p 0.00001]. Conclusion: Present data suggest that HRCT abnormalities in early-onset elderly asthmatics reflect parenchymal and airway changes that become irreversible throughout the long course of the disease

Esclerose sistêmica progressiva: aspectos na tomografia computadorizada de alta resolução Progressive systemic sclerosis: high-resolution computed tomography findings

Directory of Open Access Journals (Sweden)

Emerson L. Gasparetto

2005-09-01

Full Text Available OBJETIVO: Descrever os achados de tomografia computadorizada de alta resolução de pacientes com esclerose sistêmica pulmonar, independentemente dos sintomas respiratórios. MATERIAIS E MÉTODOS: Foram revisados 73 exames de tomografia computadorizada de alta resolução de 44 pacientes com diagnóstico de esclerodermia estabelecido através de critérios clínicos e laboratoriais. Os exames foram revisados por dois radiologistas, que estabeleceram os achados por consenso. RESULTADOS: Em 91,8% (n = 67 dos exames observaram-se alterações. Os principais achados foram lesões de padrão reticular (90,4%, opacidades em vidro-fosco (63%, bronquiectasias e bronquiolectasias de tração (56,2%, dilatação esofagiana (46,6%, faveolamento (28,8% e sinais de hipertensão pulmonar (15,6%. Na maioria dos casos as lesões eram bilaterais (89% e simétricas (58,5%. Quanto à localização, houve predomínio de lesões basais (91,2% e periféricas (92,2%. CONCLUSÃO: A esclerose sistêmica progressiva acarreta fibrose pulmonar na maioria dos pacientes, caracterizada principalmente por lesão reticular basal e periférica.OBJECTIVE: To describe the high-resolution computed tomography findings in the lung of patients with systemic sclerosis, independently of the respiratory symptoms. MATERIALS AND METHODS: Seventy-three high-resolution computed tomography scans of 44 patients with clinical diagnosis of systemic sclerosis were reviewed and defined by the consensus of two radiologists. RESULTS: Abnormalities were seen in 91.8% (n = 67 of the scans. The most frequent findings were reticular pattern (90.4%, ground-glass opacities (63%, traction bronchiectasis and bronchiolectasis (56.2%, esophageal dilatation (46.6%, honeycombing pattern (28.8% and signs of pulmonary hypertension (15.6%. In most cases the lesions were bilateral (89% and symmetrical (58.5%. The lesions were predominantly located in the basal (91.2% and peripheral (92.2% regions. CONCLUSION: In

Pictorial review: Electron beam computed tomography and multislice spiral computed tomography for cardiac imaging

International Nuclear Information System (INIS)

Lembcke, Alexander; Hein, Patrick A.; Dohmen, Pascal M.; Klessen, Christian; Wiese, Till H.; Hoffmann, Udo; Hamm, Bernd; Enzweiler, Christian N.H.

2006-01-01

Electron beam computed tomography (EBCT) revolutionized cardiac imaging by combining a constant high temporal resolution with prospective ECG triggering. For years, EBCT was the primary technique for some non-invasive diagnostic cardiac procedures such as calcium scoring and non-invasive angiography of the coronary arteries. Multislice spiral computed tomography (MSCT) on the other hand significantly advanced cardiac imaging through high volume coverage, improved spatial resolution and retrospective ECG gating. This pictorial review will illustrate the basic differences between both modalities with special emphasis to their image quality. Several experimental and clinical examples demonstrate the strengths and limitations of both imaging modalities in an intraindividual comparison for a broad range of diagnostic applications such as coronary artery calcium scoring, coronary angiography including stent visualization as well as functional assessment of the cardiac ventricles and valves. In general, our examples indicate that EBCT suffers from a number of shortcomings such as limited spatial resolution and a low contrast-to-noise ratio. Thus, EBCT should now only be used in selected cases where a constant high temporal resolution is a crucial issue, such as dynamic (cine) imaging. Due to isotropic submillimeter spatial resolution and retrospective data selection MSCT seems to be the non-invasive method of choice for cardiac imaging in general, and for assessment of the coronary arteries in particular. However, technical developments are still needed to further improve the temporal resolution in MSCT and to reduce the substantial radiation exposure

Relationships (II) of International Classification of High-resolution Computed Tomography for Occupational and Environmental Respiratory Diseases with ventilatory functions indices for parenchymal abnormalities.

Science.gov (United States)

Tamura, Taro; Suganuma, Narufumi; Hering, Kurt G; Vehmas, Tapio; Itoh, Harumi; Akira, Masanori; Takashima, Yoshihiro; Hirano, Harukazu; Kusaka, Yukinori

2015-01-01

The International Classification of High-Resolution Computed Tomography (HRCT) for Occupational and Environmental Respiratory Diseases (ICOERD) is used to screen and diagnose respiratory illnesses. Using univariate and multivariate analysis, we investigated the relationship between subject characteristics and parenchymal abnormalities according to ICOERD, and the results of ventilatory function tests (VFT). Thirty-five patients with and 27 controls without mineral-dust exposure underwent VFT and HRCT. We recorded all subjects' occupational history for mineral dust exposure and smoking history. Experts independently assessed HRCT using the ICOERD parenchymal abnormalities (Items) grades for well-defined rounded opacities (RO), linear and/or irregular opacities (IR), and emphysema (EM). High-resolution computed tomography showed that 11 patients had RO; 15 patients, IR; and 19 patients, EM. According to the multiple regression model, age and height had significant associations with many indices ventilatory functions such as vital capacity, forced vital capacity, and forced expiratory volume in 1 s (FEV1). The EM summed grades on the upper, middle, and lower zones of the right and left lungs also had significant associations with FEV1 and the maximum mid-expiratory flow rate. The results suggest the ICOERD notation is adequate based on the good and significant multiple regression modeling of ventilatory function with the EM summed grades.

Detectors for high resolution dynamic positron emission tomography

International Nuclear Information System (INIS)

Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.

1985-01-01

Tomography is the technique of producing a photographic image of an opaque specimen by transmitting a beam of x-rays or gamma rays through the specimen onto an adjacent photographic film. The image results from variations in thickness, density, and chemical composition, of the specimen. This technique is used to study the metabolism of the human brain. This article examines the design of equipment used for high resolution dynamic positron emission tomography. 27 references, 5 figures, 3 tables

High resolution computed tomography of chronic otitis media

International Nuclear Information System (INIS)

Shirahata, Yuichi; Tachibana, Toshiro; Fukami, Masaya; Onishi, Toshiro; Doi, Osamu

1986-01-01

Seventy six patients with chronic otitis media were examined by CT. Using 3 dried skulls, the epitympanum was impacted with a piece of paraffin containing of 2 % iodine, and studied with CT-scan (Toshiba 60A-30) to clarify whether or not the paraffin could produce a soft tissue density on CT which was similar to that of cholesteatoma in the middle ear. The results showed that computed tomography was excellent in demonstrating a soft tissue mass in the middle ear with inflammatory disease. When the middle ear infection with granulation tissue or cholesteatoma existed, the resulting soft tissue mass was indistinguishable. CT scanning was useful for accurate determination of location of bone destruction in the middle ear as well as of the ossicles. (author)

Efficacy of 3D-positron emission tomography/computed tomography for upper abdomen.

Science.gov (United States)

Murakami, Koji; Nakahara, Tadaki

2014-04-01

Recent advancement in computed tomography (CT) enables us to obtain high spatial resolution image and made it possible to construct extensive high-definition three-dimensional (3D) images. But a lack of contrast resolution in CT alone is still remained problem. Meanwhile, as fluorodeoxyglucose-positron emission tomography (PET) can visualize tumors in high contrast, we can create 3D images fusing the accumulation in tumors on PET/CT images. Such images can play the role of a "map of body" which makes it easy to understand the anatomical information before surgery. We also try to evaluate segmental liver function by using PET/CT fusion images. By using (11) C-methionine PET/contrast-enhanced CT, superior image quality compared to single photon emission computed tomography/CT can be obtained. CT, especially with contrast enhancement for obtaining anatomical imaging information plus PET for obtaining functional imaging information is a highly compatible combination, and adding these two types information will further increase clinical usefulness. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

Basic principle of cone beam computed tomography

International Nuclear Information System (INIS)

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

2006-01-01

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

Transverse axial plane anatomy of the temporal bone employing high spatial resolution computed tomography

International Nuclear Information System (INIS)

Russell, E.J.; Koslow, M.; Lasjaunias, P.; Bergeron, R.T.; Chase, N.

1982-01-01

Anatomical relationships of temporal bone structures are demonstrated by thin section edge detection computed tomography. Many otic structures are best appreciated in axial view, but reorientation to anatomy as seen in this plane is needed for optimal diagnosis. A level by level review of key structure is presented toward this end. The limitations and advantages of computed tomography are discussed. (orig.)

Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

DEFF Research Database (Denmark)

Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O

2010-01-01

There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

High-resolution computed tomography scan of lumbosacral spine

International Nuclear Information System (INIS)

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

1981-01-01

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

High resolution and high speed positron emission tomography data acquisition

International Nuclear Information System (INIS)

Burgiss, S.G.; Byars, L.G.; Jones, W.F.; Casey, M.E.

1986-01-01

High resolution positron emission tomography (PET) requires many detectors. Thus, data collection systems for PET must have high data rates, wide data paths, and large memories to histogram the events. This design uses the VMEbus to cost effectively provide these features. It provides for several modes of operation including real time sorting, list mode data storage, and replay of stored list mode data

[Diagnostic value of high-resolution computed tomography imaging in congenital inner ear malformations].

Science.gov (United States)

Sun, Xiaowei; Ding, Yuanping; Zhang, Jianji; Chen, Ying; Xu, Anting; Dou, Fenfen; Zhang, Zihe

2007-02-01

To observe the inner ear structure with volume rendering (VR) reconstruction and to evaluate the role of high-resolution computed tomography (HRCT) in congenital inner ear malformations. HRCT scanning was performed in 10 patients (20 ears) without ear disease (control group) and 7 patients (11 ears) with inner ear malformations (IEM group) and the original data was processed with VR reconstruction. The inner ear osseous labyrinth structure in the images generated by these techniques was observed respectively in the normal ears and malformation ears. The inner ear osseous labyrinth structure and the relationship was displayed clearly in VR imaging in the control group,meanwhile, characters and degree of malformed structure were also displayed clearly in the IEA group. Of seven patients (11 ears) with congenital inner ear malformations, the axial, MPR and VR images can display the site and degree in 9 ears. VR images were superior to the axial images in displaying the malformations in 2 ears with the small lateral semicircular canal malformations. The malformations included Mondini deformity (7 ears), vestibular and semicircular canal malformations (3 ears), vestibular aqueduct dilate (7 ears, of which 6 ears accompanied by other malformations) , the internal auditory canal malformation (2 ears, all accompanied by other malformations). HRCT can display the normal structure of bone inner ear through high quality VR reconstructions. VR images can also display the site and degree of the malformations three-dimensionally and intuitively. HRCT is valuable in diagnosing the inner ear malformation.

Pulmonary leukemic involvement: high-resolution computed tomography evaluation; Comprometimento pulmonar nas leucemias: avaliacao por tomografia computadorizada de alta resolucao

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Ana Paola de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Programa de Pos-graduacao em Radiologia; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Souza, Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Radiologia

2004-12-01

Objective: To evaluate the role of high-resolution computed tomography (HRCT) in patients with leukemia and pulmonary symptoms, to establish the main patterns and to correlate them with the etiology. Materials and Methods: This is a retrospective study of the HRCT of 15 patients with leukemia and pulmonary symptoms. The examinations were performed using a spatial high-resolution protocol and were analyzed by two independent radiologists. Results: The main HRCT patterns found were ground-glass opacity (n=11), consolidation (n=9), airspace nodules (n=3), septal thickening (n=3), tree-in-bud pattern (n=3), and pleural effusion (n=3). Pulmonary infection was the most common finding seen in 12 patients: bacterial pneumonia (n=6), fungal infection (n = 4), pulmonary tuberculosis (n=1) and viral infection (n=1). Leukemic pleural infiltration (n=1), lymphoma (n=1) and pulmonary hemorrhage (n=1) were detected in the other three patients. Conclusion: HRCT is an important tool that may suggest the cause of lung involvement, its extension and in some cases to guide invasive procedures in patients with leukemia. (author)

Three-Dimensional Imaging and Numerical Reconstruction of Graphite/Epoxy Composite Microstructure Based on Ultra-High Resolution X-Ray Computed Tomography

Science.gov (United States)

Czabaj, M. W.; Riccio, M. L.; Whitacre, W. W.

2014-01-01

A combined experimental and computational study aimed at high-resolution 3D imaging, visualization, and numerical reconstruction of fiber-reinforced polymer microstructures at the fiber length scale is presented. To this end, a sample of graphite/epoxy composite was imaged at sub-micron resolution using a 3D X-ray computed tomography microscope. Next, a novel segmentation algorithm was developed, based on concepts adopted from computer vision and multi-target tracking, to detect and estimate, with high accuracy, the position of individual fibers in a volume of the imaged composite. In the current implementation, the segmentation algorithm was based on Global Nearest Neighbor data-association architecture, a Kalman filter estimator, and several novel algorithms for virtualfiber stitching, smoothing, and overlap removal. The segmentation algorithm was used on a sub-volume of the imaged composite, detecting 508 individual fibers. The segmentation data were qualitatively compared to the tomographic data, demonstrating high accuracy of the numerical reconstruction. Moreover, the data were used to quantify a) the relative distribution of individual-fiber cross sections within the imaged sub-volume, and b) the local fiber misorientation relative to the global fiber axis. Finally, the segmentation data were converted using commercially available finite element (FE) software to generate a detailed FE mesh of the composite volume. The methodology described herein demonstrates the feasibility of realizing an FE-based, virtual-testing framework for graphite/fiber composites at the constituent level.

High resolution tomography using analog coding

International Nuclear Information System (INIS)

Brownell, G.L.; Burnham, C.A.; Chesler, D.A.

1985-01-01

As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

Diagnostic accuracy of cone-beam computed tomography scans with high- and low-resolution modes for the detection of root perforations.

Science.gov (United States)

Shokri, Abbas; Eskandarloo, Amir; Norouzi, Marouf; Poorolajal, Jalal; Majidi, Gelareh; Aliyaly, Alireza

2018-03-01

This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars. The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact (control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables. In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D. The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

Science.gov (United States)

Kakinuma, Ryutaro; Moriyama, Noriyuki; Muramatsu, Yukio; Gomi, Shiho; Suzuki, Masahiro; Nagasawa, Hirobumi; Kusumoto, Masahiko; Aso, Tomohiko; Muramatsu, Yoshihisa; Tsuchida, Takaaki; Tsuta, Koji; Maeshima, Akiko Miyagi; Tochigi, Naobumi; Watanabe, Shun-ichi; Sugihara, Naoki; Tsukagoshi, Shinsuke; Saito, Yasuo; Kazama, Masahiro; Ashizawa, Kazuto; Awai, Kazuo; Honda, Osamu; Ishikawa, Hiroyuki; Koizumi, Naoya; Komoto, Daisuke; Moriya, Hiroshi; Oda, Seitaro; Oshiro, Yasuji; Yanagawa, Masahiro; Tomiyama, Noriyuki; Asamura, Hisao

2015-01-01

Purpose The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner. Results The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures. Conclusion Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners. PMID:26352144

Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

Directory of Open Access Journals (Sweden)

Ryutaro Kakinuma

Full Text Available The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT scanners.This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner.The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU] was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001. The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001 for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

Bronchial asthma: correlation of high resolution computerized tomography findings with clinical data

International Nuclear Information System (INIS)

Mogami, Roberto; Marchiori, Edson; Kirk, Kennedy; Capone, Domenico; Daltro, Pedro

1999-01-01

In this work we did a sectional study of 31 asthmatic patients with several levels of disease severity, which were submitted to high resolution computed tomography of the thorax and spirometry, between the months of July, 1995 and August, 1997. The tomographic findings were correlated with the clinical classification of the patients and the most frequent tomographic findings were bronchial wall thickening, bronchial dilatation, air trapping, centrilobular opacities, cicatricial linear shadows, mucoid impaction, emphysema and atelectasis. In asthmatic patients of long duration we observed small airway disease and irreversible lesions as the predominant findings. In smoking patients there was no high frequency of emphysema. (author)

Isotropic-resolution linear-array-based photoacoustic computed tomography through inverse Radon transform

Science.gov (United States)

Li, Guo; Xia, Jun; Li, Lei; Wang, Lidai; Wang, Lihong V.

2015-03-01

Linear transducer arrays are readily available for ultrasonic detection in photoacoustic computed tomography. They offer low cost, hand-held convenience, and conventional ultrasonic imaging. However, the elevational resolution of linear transducer arrays, which is usually determined by the weak focus of the cylindrical acoustic lens, is about one order of magnitude worse than the in-plane axial and lateral spatial resolutions. Therefore, conventional linear scanning along the elevational direction cannot provide high-quality three-dimensional photoacoustic images due to the anisotropic spatial resolutions. Here we propose an innovative method to achieve isotropic resolutions for three-dimensional photoacoustic images through combined linear and rotational scanning. In each scan step, we first elevationally scan the linear transducer array, and then rotate the linear transducer array along its center in small steps, and scan again until 180 degrees have been covered. To reconstruct isotropic three-dimensional images from the multiple-directional scanning dataset, we use the standard inverse Radon transform originating from X-ray CT. We acquired a three-dimensional microsphere phantom image through the inverse Radon transform method and compared it with a single-elevational-scan three-dimensional image. The comparison shows that our method improves the elevational resolution by up to one order of magnitude, approaching the in-plane lateral-direction resolution. In vivo rat images were also acquired.

Forward transformation for high resolution eddy current tomography using whitney elements

International Nuclear Information System (INIS)

Szewczyk, R.; Salach, J.; Nowicki, M.; Ruokolainen, J.; Raback, P.

2014-01-01

Tomographic methods are intensively developed field of non-destructive testing. The main advantage of this type of NDT method is 3D information concerning the shape of the discontinuities in investigated material. On the other hand, the most common tomography method utilizing X-rays creates the significant risks typical to X-ray technique. As a result, Xray tomography is difficult to use in industry. Introduced to the industry in 2007, the eddy current tomography is safe and cost effective. However, in opposite to X-ray tomography, eddy current tomography requires sophisticated and time consuming inverse transformation creating 2D or 3D view of discontinuities. For this reason solutions presented previously are focused on 2D inverse transformation and exhibit limited resolution. For eddy current tomography, the forward tomographic transformation is most important, which is the base of inverse transformation. This paper presents the novel, fast and cost-effective solution utilizing Whitney elements method for such forward transformation. As a result, new possibilities of development in the area of high resolution 3D eddy current tomography are created. (authors)

Flat-Panel Computed Tomography (DYNA-CT) in Neuroradiology. From High-Resolution Imaging of Implants to One-Stop-Shopping for Acute Stroke.

Science.gov (United States)

Doerfler, A; Gölitz, P; Engelhorn, T; Kloska, S; Struffert, T

2015-10-01

Originally aimed at improving standard radiography by providing higher absorption efficiency and a wider dynamic range, flat-panel detector technology has meanwhile got widely accepted in the neuroradiological community. Especially flat-panel detector computed tomography (FD-CT) using rotational C-arm mounted flat-panel detector technology is capable of volumetric imaging with a high spatial resolution. By providing CT-like images of the brain within the angio suite, FD-CT is able to rapidly visualize hemorrhage and may thus improve complication management without the need of patient transfer. As "Angiographic CT" FD-CT may be helpful during many diagnostic and neurointerventional procedures and for noninvasive monitoring and follow-up. In addition, spinal interventions and high-resolution imaging of the temporal bone might also benefit from FD-CT. Finally, using novel dynamic perfusion and angiographic protocols, FD-CT may provide functional information on brain perfusion and vasculature with the potential to replace standard imaging in selected acute stroke patients.

Radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography

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Brito, Milene Carneiro Barbosa de, E-mail: milenebrito7@gmail.com [Clinica da Imagem do Tocantins, Araguaia, TO (Brazil); Ota, Mauricio Kenji [Fundacao Instituto de Pesquisa e Estudos de Diagnostico por Imagem (FIDI), Sao Paulo, SP (Brazil); Leitao Filho, Fernando Sergio Studart [Universidade de Fortaleza (UNIFOR), Fortaleza, CE (Brazil); Meirelles, Gustavo de Souza Portes [Grupo Fleury, Sao Paulo, SP (Brazil)

2017-01-15

Objective: To evaluate radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography (HRCT). Materials and Methods: The HRCT scans of 43 patients with bronchiectasis were analyzed by two radiologists, who used a scoring system to grade the findings. Kappa (κ) values and overall agreement were calculated. Results: For the measurement and appearance of bronchiectasis, the interobserver agreement was moderate (κ = 0.45 and κ = 0.43, respectively), as was the intraobserver agreement (κ = 0.54 and κ = 0.47, respectively). Agreement on the presence of mucous plugging was fair, for central distribution (overall interobserver agreement of 68.3% and κ = 0.39 for intraobserver agreement) and for peripheral distribution (κ = 0.34 and κ = 0.35 for interobserver and intraobserver agreement, respectively). The agreement was also fair for peri bronchial thickening (κ = 0.21 and κ = 0.30 for interobserver and intraobserver agreement, respectively). There was fair interobserver and intraobserver agreement on the detection of opacities (κ = 0.39 and 71.9%, respectively), ground-glass attenuation (64.3% and κ = 0.24, respectively), and cysts/bullae (κ = 0.47 and κ = 0.44, respectively). Qualitative analysis of the HRCT findings of bronchiectasis and the resulting individual patient scores showed that there was an excellent correlation between the observers (intra class correlation coefficient of 0.85 and 0.81 for interobserver and intraobserver agreement, respectively). Conclusion: In the interpretation of HRCT findings of bronchiectasis, radiologist agreement appears to be fair. In our final analysis of the findings using the proposed score, we observed excellent interobserver and intraobserver agreement. (author)

Radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography

International Nuclear Information System (INIS)

Brito, Milene Carneiro Barbosa de; Ota, Mauricio Kenji; Leitao Filho, Fernando Sergio Studart; Meirelles, Gustavo de Souza Portes

2017-01-01

Objective: To evaluate radiologist agreement on the quantification of bronchiectasis by high-resolution computed tomography (HRCT). Materials and Methods: The HRCT scans of 43 patients with bronchiectasis were analyzed by two radiologists, who used a scoring system to grade the findings. Kappa (κ) values and overall agreement were calculated. Results: For the measurement and appearance of bronchiectasis, the interobserver agreement was moderate (κ = 0.45 and κ = 0.43, respectively), as was the intraobserver agreement (κ = 0.54 and κ = 0.47, respectively). Agreement on the presence of mucous plugging was fair, for central distribution (overall interobserver agreement of 68.3% and κ = 0.39 for intraobserver agreement) and for peripheral distribution (κ = 0.34 and κ = 0.35 for interobserver and intraobserver agreement, respectively). The agreement was also fair for peri bronchial thickening (κ = 0.21 and κ = 0.30 for interobserver and intraobserver agreement, respectively). There was fair interobserver and intraobserver agreement on the detection of opacities (κ = 0.39 and 71.9%, respectively), ground-glass attenuation (64.3% and κ = 0.24, respectively), and cysts/bullae (κ = 0.47 and κ = 0.44, respectively). Qualitative analysis of the HRCT findings of bronchiectasis and the resulting individual patient scores showed that there was an excellent correlation between the observers (intra class correlation coefficient of 0.85 and 0.81 for interobserver and intraobserver agreement, respectively). Conclusion: In the interpretation of HRCT findings of bronchiectasis, radiologist agreement appears to be fair. In our final analysis of the findings using the proposed score, we observed excellent interobserver and intraobserver agreement. (author)

Radiation dose in cone-beam computed tomography: myth or reality

International Nuclear Information System (INIS)

Madi, Medhini

2013-01-01

In the growing inventory of clinical computed tomography technologies, cone-beam X-ray computed tomography is a relatively recent instalment. It is an advancement in computed tomography imaging which is designed to provide relatively low-dose high-spatial-resolution visualization of high contrast structures in the head and neck and other anatomic areas. Comparatively low dosing requirements and relatively compact design has led to intense interest in surgical planning and intra-operative cone-beam computed tomography applications, particularly in head and neck, and also in spinal, thoracic, abdominal and orthopaedic procedures. The use of this emerging imaging technology, which has potential applications for imaging of high-contrast structures in the head and neck as well as dentomaxillofacial regions, has been the subject of criticism as well as acclaim. This paper envisages to discuss the state-of-the-art of the technique. (author)

Potentials of high resolution magnetic resonance imaging versus computed tomography for preoperative local staging of colon cancer

International Nuclear Information System (INIS)

Rollven, Erik; Blomqvist, Lennart; Holm, Torbjorn; Glimelius, Bengt; Loerinc, Esther

2013-01-01

Background: Preoperative identification of locally advanced colon cancer is of importance in order to properly plan treatment. Purpose: To study high resolution T2-weighted magnetic resonance imaging (MRI) versus computed tomography (CT) for preoperative staging of colon cancer with surgery and histopathology as reference standard. Material and Methods: Twenty-eight patients with a total of 29 tumors were included. Patients were examined on a 1.5 T MR unit using a phased array body coil. T2 turbo spin-echo high resolution sequences were obtained in a coronal, transverse, and perpendicular plane to the long axis of the colon at the site of the tumor. Contrast-enhanced CT was performed using a protocol for metastasis staging. The examinations were independently evaluated by two gastrointestinal radiologists using criteria adapted to imaging for prediction of T-stage, N-stage, and extramural venous invasion. Based on the T-stage, tumors were divided in to locally advanced (T3cd-T4) and not locally advanced (T1-T3ab). Surgical and histopathological findings served as reference standard. Results: Using MRI, T-stage, N-stage, and extramural venous invasion were correctly predicted for each observer in 90% and 93%, 72% and 69%, and 82% and 78% of cases, respectively. With CT the corresponding results were 79% and 76%, 72% and 72%, 78% and 67%. For MRI inter-observer agreements (Kappa statistics) were 0.79, 0.10, and 0.76. For CT the corresponding results were 0.64, 0.66, and 0.22. Conclusion: Patients with locally advanced colon cancer, defined as tumor stage T3cd-T4, can be identified by both high resolution MRI and CT, even when CT is performed with a metastasis staging protocol. MRI may have an advantage, due to its high soft tissue discrimination, to identify certain prognostic factors such as T-stage and extramural venous invasion

Potentials of high resolution magnetic resonance imaging versus computed tomography for preoperative local staging of colon cancer

Energy Technology Data Exchange (ETDEWEB)

Rollven, Erik; Blomqvist, Lennart [Dept. of Diagnostic Radiology, Karolinska Univ. Hospital Solna, Stockholm (Sweden); Dept. of Molecular Medicine and Surgery, Karolinska Inst., Stockholm (Sweden)], e-mail: erik.rollven@ki.se; Holm, Torbjorn [Dept. of Molecular Medicine and Surgery, Karolinska Inst., Stockholm (Sweden); Dept. of Surgery, Karolinska Univ. Hospital Solna, Stockholm (Sweden); Glimelius, Bengt [Dept. of Radiology, Oncology and Radiation Science, Uppsala Univ., Uppsala (Sweden); Dept. of Oncology and Pathology, Karolinska Inst., Stockholm (Sweden); Loerinc, Esther [Dept. of Oncology and Pathology, Karolinska Inst., Stockholm (Sweden); Dept. of Pathology, Karolinska Univ. Hospital, Solna, Sweden (Sweden)

2013-09-15

Background: Preoperative identification of locally advanced colon cancer is of importance in order to properly plan treatment. Purpose: To study high resolution T2-weighted magnetic resonance imaging (MRI) versus computed tomography (CT) for preoperative staging of colon cancer with surgery and histopathology as reference standard. Material and Methods: Twenty-eight patients with a total of 29 tumors were included. Patients were examined on a 1.5 T MR unit using a phased array body coil. T2 turbo spin-echo high resolution sequences were obtained in a coronal, transverse, and perpendicular plane to the long axis of the colon at the site of the tumor. Contrast-enhanced CT was performed using a protocol for metastasis staging. The examinations were independently evaluated by two gastrointestinal radiologists using criteria adapted to imaging for prediction of T-stage, N-stage, and extramural venous invasion. Based on the T-stage, tumors were divided in to locally advanced (T3cd-T4) and not locally advanced (T1-T3ab). Surgical and histopathological findings served as reference standard. Results: Using MRI, T-stage, N-stage, and extramural venous invasion were correctly predicted for each observer in 90% and 93%, 72% and 69%, and 82% and 78% of cases, respectively. With CT the corresponding results were 79% and 76%, 72% and 72%, 78% and 67%. For MRI inter-observer agreements (Kappa statistics) were 0.79, 0.10, and 0.76. For CT the corresponding results were 0.64, 0.66, and 0.22. Conclusion: Patients with locally advanced colon cancer, defined as tumor stage T3cd-T4, can be identified by both high resolution MRI and CT, even when CT is performed with a metastasis staging protocol. MRI may have an advantage, due to its high soft tissue discrimination, to identify certain prognostic factors such as T-stage and extramural venous invasion.

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.

Computed tomography

International Nuclear Information System (INIS)

Wells, P.; Davis, J.; Morgan, M.

1994-01-01

X-ray or gamma-ray transmission computed tomography (CT) is a powerful non-destructive evaluation (NDE) technique that produces two-dimensional cross-sectional images of an object without the need to physically section it. CT is also known by the acronym CAT, for computerised axial tomography. This review article presents a brief historical perspective on CT, its current status and the underlying physics. The mathematical fundamentals of computed tomography are developed for the simplest transmission CT modality. A description of CT scanner instrumentation is provided with an emphasis on radiation sources and systems. Examples of CT images are shown indicating the range of materials that can be scanned and the spatial and contrast resolutions that may be achieved. Attention is also given to the occurrence, interpretation and minimisation of various image artefacts that may arise. A final brief section is devoted to the principles and potential of a range of more recently developed tomographic modalities including diffraction CT, positron emission CT and seismic tomography. 57 refs., 2 tabs., 14 figs

A high time and spatial resolution MRPC designed for muon tomography

Science.gov (United States)

Shi, L.; Wang, Y.; Huang, X.; Wang, X.; Zhu, W.; Li, Y.; Cheng, J.

2014-12-01

A prototype of cosmic muon scattering tomography system has been set up in Tsinghua University in Beijing. Multi-gap Resistive Plate Chamber (MRPC) is used in the system to get the muon tracks. Compared with other detectors, MRPC can not only provide the track but also the Time of Flight (ToF) between two detectors which can estimate the energy of particles. To get a more accurate track and higher efficiency of the tomography system, a new type of high time and two-dimensional spatial resolution MRPC has been developed. A series of experiments have been done to measure the efficiency, time resolution and spatial resolution. The results show that the efficiency can reach 95% and its time resolution is around 65 ps. The cluster size is around 4 and the spatial resolution can reach 200 μ m.

F-18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Appearance of Extramedullary Hematopoesis in a Case of Primary Myelofibrosis

Science.gov (United States)

Mukherjee, Anirban; Bal, Chandrasekhar; Tripathi, Madhavi; Das, Chandan Jyoti; Shamim, Shamim Ahmed

2017-01-01

A 44-year-old female with known primary myelofibrosis presented with shortness of breath. High Resolution Computed Tomography thorax revealed large heterogeneously enhancing extraparenchymal soft tissue density mass involving bilateral lung fields. F-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography revealed mildly FDG avid soft tissue density mass with specks of calcification involving bilateral lung fields, liver, and spleen. Subsequent histopathologic evaluation from the right lung mass was suggestive of extramedullary hematopoesis. PMID:28533647

Ultra-high resolution C-Arm CT arthrography of the wrist: Radiation dose and image quality compared to conventional multidetector computed tomography

Energy Technology Data Exchange (ETDEWEB)

Werncke, Thomas, E-mail: Werncke.Thomas@mh-hannover.de [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Sonnow, Lena; Meyer, Bernhard C. [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Lüpke, Matthias [University of Veterinary Medicine Hannover, Institute for General Radiology and Medical Physics, Bischofsholer Damm 15, 30173 Hannover (Germany); Hinrichs, Jan; Wacker, Frank K.; Falck, Christian von [Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany)

2017-04-15

Objective: Objective of this phantom and cadaveric study was to compare the effective radiation dose (ED) and image quality (IQ) between C-arm computed tomography (CACT) using an ultra-high resolution 1 × 1 binning with a standard 16-slice CT (MDCT) arthrography of the wrist. Methods: ED was determined with thermoluminescence dosimetry using an anthropomorphic phantom and different patient positions. Imaging was conducted in 10 human cadaveric wrists after tri-compartmental injection of diluted iodinated contrast material and a wire phantom. IQ of MDCT was compared with CACT reconstructed with a soft (CACT1) and sharp (CACT2) kernel. High and low contrast resolution was determined. Three radiologists assessed IQ of wrist structures and occurrence of image artifacts using a 5-point Likert scale. Results: ED of MDCT was comparable to standard CACT (4.3 μSv/3.7 μSv). High contrast resolution was best for CACT2, decreased to CACT1 and MDCT. Low contrast resolution increased between CACT2 and MDCT (P < 0.001). IQ was best for CACT2 (1.3 ± 0.5), decreased to CACT1 (1.9 ± 0.6) and MDCT (3.5 ± 0.6). Non-compromising artifacts were only reported for CACT. Conclusions: The results of this phantom and cadaveric study indicate that ultra-high resolution C-Arm CT arthrography of the wrist bears the potential to outperform MDCT arthrography in terms of image quality and workflow at the cost of mildly increasing image artifacts while radiation dose to the patient is comparably low for both, MDCT and C-Arm CT.

A tomografia computadorizada de alta resolução na avaliação da toxicidade pulmonar por amiodarona High-resolution computed tomography of amiodarone pulmonary toxicity

Directory of Open Access Journals (Sweden)

Daniela Peixoto Consídera

2006-04-01

Full Text Available OBJETIVO: Avaliar as principais alterações identificadas na tomografia computadorizada de alta resolução do tórax em pacientes com toxicidade pulmonar pela amiodarona. MATERIAIS E MÉTODOS: Foram avaliadas dez tomografias computadorizadas de alta resolução de tórax de pacientes com pneumonite pela amiodarona, seis desses pacientes do sexo masculino e quatro do sexo feminino, com idade média de 73,5 anos. RESULTADOS: Os achados tomográficos mais relevantes foram opacidades lineares ou reticulares em seis casos (60%, pequenos nódulos com densidade elevada em seis casos (60%, consolidações densas em três casos (30% e aumento da densidade do parênquima hepático em cinco de oito casos em que havia estudo tomográfico do abdome superior (62,5%. CONCLUSÃO: A tomografia computadorizada de alta resolução é um exame importante na avaliação de pacientes com toxicidade pulmonar pela amiodarona, devendo ser realizada sempre que houver suspeita deste diagnóstico. O achado de espessamento de septos interlobulares associado a lesões com aumento de densidade é altamente sugestivo deste diagnóstico.OBJECTIVE: To evaluate the main findings of chest high-resolution computed tomography in patients with amiodarone pulmonary toxicity. MATERIALS AND METHODS: Ten patients - six male and four female, average age of 73.5 years - with amiodarone-induced pneumonitis have undergone chest high-resolution computed tomography. RESULTS: The most relevant tomographic findings were linear or reticular opacities in six cases (60%, small high density nodules in six cases (60%, dense consolidations in three cases (30% and increased density in the hepatic parenchyma in five of eight cases in which there was a superior abdomen CT scan (62.5%. CONCLUSION: The high-resolution computed tomography is a valuable non-invasive test for evaluating patients with amiodarone pulmonary toxicity and should always be performed when one suspects of the presence of this

Effects of pure and hybrid iterative reconstruction algorithms on high-resolution computed tomography in the evaluation of interstitial lung disease.

Science.gov (United States)

Katsura, Masaki; Sato, Jiro; Akahane, Masaaki; Mise, Yoko; Sumida, Kaoru; Abe, Osamu

2017-08-01

To compare image quality characteristics of high-resolution computed tomography (HRCT) in the evaluation of interstitial lung disease using three different reconstruction methods: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Eighty-nine consecutive patients with interstitial lung disease underwent standard-of-care chest CT with 64-row multi-detector CT. HRCT images were reconstructed in 0.625-mm contiguous axial slices using FBP, ASIR, and MBIR. Two radiologists independently assessed the images in a blinded manner for subjective image noise, streak artifacts, and visualization of normal and pathologic structures. Objective image noise was measured in the lung parenchyma. Spatial resolution was assessed by measuring the modulation transfer function (MTF). MBIR offered significantly lower objective image noise (22.24±4.53, PASIR (39.76±7.41) and FBP (51.91±9.71). MTF (spatial resolution) was increased using MBIR compared with ASIR and FBP. MBIR showed improvements in visualization of normal and pathologic structures over ASIR and FBP, while ASIR was rated quite similarly to FBP. MBIR significantly improved subjective image noise (PASIR and FBP. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a lab-scale, high-resolution, tube-generated X-ray computed-tomography system for three-dimensional (3D) materials characterization

International Nuclear Information System (INIS)

Mertens, J.C.E.; Williams, J.J.; Chawla, Nikhilesh

2014-01-01

The design and construction of a modular high resolution X-ray computed tomography (XCT) system is highlighted in this paper. The design approach is detailed for meeting a specified set of instrument performance goals tailored towards experimental versatility and high resolution imaging. The XCT tool is unique in the detector and X-ray source design configuration, enabling control in the balance between detection efficiency and spatial resolution. The system package is also unique: The sample manipulation approach implemented enables a wide gamut of in situ experimentation to analyze structure evolution under applied stimulus, by optimizing scan conditions through a high degree of controllability. The component selection and design process is detailed: Incorporated components are specified, custom designs are shared, and the approach for their integration into a fully functional XCT scanner is provided. Custom designs discussed include the dual-target X-ray source cradle which maintains position and trajectory of the beam between the two X-ray target configurations with respect to a scintillator mounting and positioning assembly and the imaging sensor, as well as a novel large-format X-ray detector with enhanced adaptability. The instrument is discussed from an operational point of view, including the details of data acquisition and processing implemented for 3D imaging via micro-CT. The performance of the instrument is demonstrated on a silica-glass particle/hydroxyl-terminated-polybutadiene (HTPB) matrix binder PBX simulant. Post-scan data processing, specifically segmentation of the sample's relevant microstructure from the 3D reconstruction, is provided to demonstrate the utility of the instrument. - Highlights: • Custom built X-ray tomography system for microstructural characterization • Detector design for maximizing polychromatic X-ray detection efficiency • X-ray design offered for maximizing X-ray flux with respect to imaging resolution �

Development of sealed sample containers and high resolution micro-tomography

Energy Technology Data Exchange (ETDEWEB)

Uesugi, Kentaro, E-mail: ueken@spring8.or.jp; Takeuchi, Akihisa; Suzuki, Yoshio [Japan synchrotron radiation research institute, JASRI/SPring-8 Kouto 1-1-1, Sayo, Hyogo 679-5198 Japan (Japan); Uesugi, Masayuki [Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Hamada, Hiroshi [NTT Advanced technology Corporation, Atsugi, Kanagawa 243-0124 (Japan)

2016-01-28

A sample container and a high resolution micro-tomography system have been developed at BL47XU at SPring-8. The container is made of a SiN membrane in a shape of truncated pyramid, which makes it possible to exclude oxygen and moisture in the air. The sample rotation stage for tomography is set downward to keep the sample in the container without any glue. The spatial resolution and field of view are 300 nm and 110 μm using a Fresnel zone plate objective with an outermost zone width of 100 nm at 8 keV, respectively. The scan time is about 20 minutes for 1800 projections. A 3-D image of an asteroid particle was successfully obtained without adhesive and contamination.

High-resolution 3D imaging of polymerized photonic crystals by lab-based x-ray nanotomography with 50-nm resolution

Science.gov (United States)

Yin, Leilei; Chen, Ying-Chieh; Gelb, Jeff; Stevenson, Darren M.; Braun, Paul A.

2010-09-01

High resolution x-ray computed tomography is a powerful non-destructive 3-D imaging method. It can offer superior resolution on objects that are opaque or low contrast for optical microscopy. Synchrotron based x-ray computed tomography systems have been available for scientific research, but remain difficult to access for broader users. This work introduces a lab-based high-resolution x-ray nanotomography system with 50nm resolution in absorption and Zernike phase contrast modes. Using this system, we have demonstrated high quality 3-D images of polymerized photonic crystals which have been analyzed for band gap structures. The isotropic volumetric data shows excellent consistency with other characterization results.

The micro-mechanics of strength, durability and damage tolerance in composites: new insights from high resolution computed tomography

Science.gov (United States)

Spearing, S. Mark; Sinclair, Ian

2016-07-01

Recent work, led by the authors, on impact damage resistance, particle toughening and tensile fibre failure is reviewed in order to illustrate the use of high-resolution X-ray tomography to observe and quantify damage mechanisms in carbon fibre composite laminates. Using synchrotron and micro-focus X-ray sources resolutions of less than 1 μm have been routinely achieved. This enables individual broken fibres and the micromechanisms of particle toughening to be observed and quantified. The data for fibre failure, cluster formation and overall tensile strength are compared with model predictions. This allows strategies for future model development to be identified. The overall implications for using such high-resolution 3-D measurements to inform a “data-rich mechanics” approach to materials evaluation and modeling is discussed.

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

Clinical, pathological, and radiological characteristics of solitary ground-glass opacity lung nodules on high-resolution computed tomography

Directory of Open Access Journals (Sweden)

Qiu ZX

2016-09-01

Full Text Available Zhi-Xin Qiu,1 Yue Cheng,1 Dan Liu,1 Wei-Ya Wang,2 Xia Wu,2 Wei-Lu Wu,2 Wei-Min Li1,2 1Department of Respiratory Medicine, 2Department of Pathology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Background: Lung nodules are being detected at an increasing rate year by year with high-resolution computed tomography (HRCT being widely used. Ground-glass opacity nodule is one of the special types of pulmonary nodules that is confirmed to be closely associated with early stage of lung cancer. Very little is known about solitary ground-glass opacity nodules (SGGNs. In this study, we analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT.Methods: A total of 95 resected SGGNs were evaluated with HRCT scan. The clinical, pathological, and radiological characteristics of these cases were analyzed.Results: Eighty-one adenocarcinoma and 14 benign nodules were observed. The nodules included 12 (15% adenocarcinoma in situ (AIS, 14 (17% minimally invasive adenocarcinoma (MIA, and 55 (68% invasive adenocarcinoma (IA. No patients with recurrence till date have been identified. The positive expression rates of anaplastic lymphoma kinase and ROS-1 (proto-oncogene tyrosine-protein kinase ROS were only 2.5% and 8.6%, respectively. The specificity and accuracy of HRCT of invasive lung adenocarcinoma were 85.2% and 87.4%. The standard uptake values of only two patients determined by 18F-FDG positron emission tomography/computed tomography (PET/CT were above 2.5. The size, density, shape, and pleural tag of nodules were significant factors that differentiated IA from AIS and MIA. Moreover, the size, shape, margin, pleural tag, vascular cluster, bubble-like sign, and air bronchogram of nodules were significant determinants for mixed ground-glass opacity nodules (all P<0.05.Conclusion: We analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT and found that the size, density

High-resolution computed tomography in silicosis: correlation with chest radiography and pulmonary function tests

Energy Technology Data Exchange (ETDEWEB)

Lopes, Agnaldo Jose [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Pedro Ernesto Univ. Hospital. Dept. of Respiratory Function]. E-mail: phel.lop@uol.com.br; Mogami, Roberto; Capone, Domenico; Jansen, Jose Manoel [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). School of Medical Sciences; Tessarollo, Bernardo [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Dept. of Radiology and Diagnostic Image; Melo, Pedro Lopes de [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. of Biology

2008-05-15

Objective: To correlate tomographic findings with pulmonary function findings, as well as to compare chest X-ray findings with high-resolution computed tomography (HRCT) findings, in patients with silicosis. Methods: A cross-sectional study was conducted in 44 non-smoking patients without a history of tuberculosis. Chest X-ray findings were classified according to the International Labour Organization recommendations. Using a semiquantitative system, the following HRCT findings were measured: the full extent of pulmonary involvement; parenchymal opacities; and emphysema. Spirometry and forced oscillation were performed. Pulmonary volumes were evaluated using the helium dilution method, and diffusing capacity of the lung for carbon monoxide was assessed. Results: Of the 44 patients studied, 41 were male. The mean age was 48.4 years. There were 4 patients who were classified as category 0 based on X-ray findings and as category 1 based on HRCT findings. Using HRCT scans, we identified progressive massive fibrosis in 33 patients, compared with only 23 patients when X-rays were used. Opacity score was found to correlate most closely with airflow, DLCO and compliance. Emphysema score correlated inversely with volume, DLCO and airflow. In this sample of patients presenting a predominance of large opacities (75% of the individuals), the deterioration of pulmonary function was associated with the extent of structural changes. Conclusions: In the early detection of silicosis and the identification of progressive massive fibrosis, HRCT scans are superior to X-rays. (author)

High-resolution computed tomography in silicosis: correlation with chest radiography and pulmonary function tests

International Nuclear Information System (INIS)

Lopes, Agnaldo Jose; Mogami, Roberto; Capone, Domenico; Jansen, Jose Manoel; Tessarollo, Bernardo; Melo, Pedro Lopes de

2008-01-01

Objective: To correlate tomographic findings with pulmonary function findings, as well as to compare chest X-ray findings with high-resolution computed tomography (HRCT) findings, in patients with silicosis. Methods: A cross-sectional study was conducted in 44 non-smoking patients without a history of tuberculosis. Chest X-ray findings were classified according to the International Labour Organization recommendations. Using a semiquantitative system, the following HRCT findings were measured: the full extent of pulmonary involvement; parenchymal opacities; and emphysema. Spirometry and forced oscillation were performed. Pulmonary volumes were evaluated using the helium dilution method, and diffusing capacity of the lung for carbon monoxide was assessed. Results: Of the 44 patients studied, 41 were male. The mean age was 48.4 years. There were 4 patients who were classified as category 0 based on X-ray findings and as category 1 based on HRCT findings. Using HRCT scans, we identified progressive massive fibrosis in 33 patients, compared with only 23 patients when X-rays were used. Opacity score was found to correlate most closely with airflow, DLCO and compliance. Emphysema score correlated inversely with volume, DLCO and airflow. In this sample of patients presenting a predominance of large opacities (75% of the individuals), the deterioration of pulmonary function was associated with the extent of structural changes. Conclusions: In the early detection of silicosis and the identification of progressive massive fibrosis, HRCT scans are superior to X-rays. (author)

Breaking the Crowther limit: Combining depth-sectioning and tilt tomography for high-resolution, wide-field 3D reconstructions

International Nuclear Information System (INIS)

Hovden, Robert; Ercius, Peter; Jiang, Yi; Wang, Deli; Yu, Yingchao; Abruña, Héctor D.; Elser, Veit; Muller, David A.

2014-01-01

To date, high-resolution ( 6 nm) to appear blurred or missing. Here we demonstrate a three-dimensional imaging method that overcomes both these limits by combining through-focal depth sectioning and traditional tilt-series tomography to reconstruct extended objects, with high-resolution, in all three dimensions. The large convergence angle in aberration corrected instruments now becomes a benefit and not a hindrance to higher quality reconstructions. A through-focal reconstruction over a 390 nm 3D carbon support containing over 100 dealloyed and nanoporous PtCu catalyst particles revealed with sub-nanometer detail the extensive and connected interior pore structure that is created by the dealloying instability. - Highlights: • Develop tomography technique for high-resolution and large field of view. • We combine depth sectioning with traditional tilt tomography. • Through-focal tomography reduces tilts and improves resolution. • Through-focal tomography overcomes the fundamental Crowther limit. • Aberration-corrected becomes a benefit and not a hindrance for tomography

High-resolution tomography of positron emitters with clustered pinhole SPECT

Energy Technology Data Exchange (ETDEWEB)

Goorden, Marlies C; Beekman, Freek J [Section of Radiation Detection and Medical Imaging, Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)], E-mail: m.c.goorden@tudelft.nl

2010-03-07

State-of-the-art small-animal single photon emission computed tomography (SPECT) enables sub-half-mm resolution imaging of radio-labelled molecules. Due to severe photon penetration through pinhole edges, current multi-pinhole SPECT is not suitable for high-resolution imaging of photons with high energies, such as the annihilation photons emitted by positron emitting tracers (511 keV). To deal with this edge penetration, we introduce here clustered multi-pinhole SPECT (CMP): each pinhole in a cluster has a narrow opening angle to reduce photon penetration. Using simulations, CMP is compared with (i) a collimator with traditional pinholes that is currently used for sub-half-mm imaging of SPECT isotopes (U-SPECT-II), and (ii), like (i) but with collimator thickness adapted to image high-energy photons (traditional multi-pinhole SPECT, TMP). At 511 keV, U-SPECT-II is able to resolve the 0.9 mm rods of an iteratively reconstructed Jaszczak-like capillary hot rod phantom, and while TMP only leads to small improvements, CMP can resolve rods as small as 0.7 mm. Using a digital tumour phantom, we show that CMP resolves many details not assessable with standard USPECT-II and TMP collimators. Furthermore, CMP makes it possible to visualize uptake of positron emitting tracers in sub-compartments of a digital mouse striatal brain phantom. This may open up unique possibilities for analysing processes such as those underlying the function of neurotransmitter systems. Additional potential of CMP may include (i) the imaging of other high-energy single-photon emitters (e.g. I-131) and (ii) localized imaging of positron emitting tracers simultaneously with single photon emitters, with an even better resolution than coincidence PET.

High-resolution multimodal clinical multiphoton tomography of skin

Science.gov (United States)

König, Karsten

2011-03-01

This review focuses on multimodal multiphoton tomography based on near infrared femtosecond lasers. Clinical multiphoton tomographs for 3D high-resolution in vivo imaging have been placed into the market several years ago. The second generation of this Prism-Award winning High-Tech skin imaging tool (MPTflex) was introduced in 2010. The same year, the world's first clinical CARS studies have been performed with a hybrid multimodal multiphoton tomograph. In particular, non-fluorescent lipids and water as well as mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen has been imaged with submicron resolution in patients suffering from psoriasis. Further multimodal approaches include the combination of multiphoton tomographs with low-resolution wide-field systems such as ultrasound, optoacoustical, OCT, and dermoscopy systems. Multiphoton tomographs are currently employed in Australia, Japan, the US, and in several European countries for early diagnosis of skin cancer, optimization of treatment strategies, and cosmetic research including long-term testing of sunscreen nanoparticles as well as anti-aging products.

Changes in bone macro- and microstructure in diabetic obese mice revealed by high resolution microfocus X-ray computed tomography

Science.gov (United States)

Kerckhofs, G.; Durand, M.; Vangoitsenhoven, R.; Marin, C.; van der Schueren, B.; Carmeliet, G.; Luyten, F. P.; Geris, L.; Vandamme, K.

2016-10-01

High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging.

Changes in bone macro- and microstructure in diabetic obese mice revealed by high resolution microfocus X-ray computed tomography

Science.gov (United States)

Kerckhofs, G.; Durand, M.; Vangoitsenhoven, R.; Marin, C.; Van der Schueren, B.; Carmeliet, G.; Luyten, F. P.; Geris, L.; Vandamme, K.

2016-01-01

High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging. PMID:27759061

High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography

Science.gov (United States)

Olivier, Scot S.; Werner, John S.; Zawadzki, Robert J.; Laut, Sophie P.; Jones, Steven M.

2010-09-07

This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

Chronic hypersensitivity pneumonitis: high resolution computed tomography patterns and pulmonary function indices as prognostic determinants

International Nuclear Information System (INIS)

Walsh, Simon L.F.; Devaraj, Anand; Hansell, David M.; Sverzellati, Nicola; Wells, Athol U.

2012-01-01

To investigate high resolution computed tomography (HRCT) and pulmonary function indices (PFTs) for determining prognosis in patients with chronic fibrotic hypersensitivity pneumonitis (CHP). Case records, PFTs (FEV 1 , FVC and DLco) and HRCTs of ninety-two patients with chronic hypersensitivity pneumonitis were evaluated. HRCT studies were scored by two observers for total disease extent, ground-glass opacification, fine and coarse reticulation, microcystic and macrocystic honeycombing, centrilobular emphysema and consolidation. Traction bronchiectasis within each pattern was graded. Using Cox proportional hazards regression models the prognostic strength of individual HRCT patterns and pulmonary function test variables were determined. There were forty two deaths during the study period. Increasing severity of traction bronchiectasis was the strongest predictor of mortality (HR 1.10, P < 0.001, 95%CI 1.04-1.16). Increasing global interstitial disease extent (HR 1.02, P = 0.02, 95%CI 1.00-1.03), microcystic honeycombing (HR 1.09, P = 0.019, 95%CI 1.01-1.17) and macrocystic honeycombing (HR 1.06, P < 0.01, 95%CI 1.01-1.10) were also independent predictors of mortality. In contrast, no individual PFT variable was predictive of mortality once HRCT patterns were accounted for. HRCT patterns, in particular, severity of traction bronchiectasis and extent of honeycombing are superior to pulmonary function tests for predicting mortality in patients with CHP. (orig.)

Chronic hypersensitivity pneumonitis: high resolution computed tomography patterns and pulmonary function indices as prognostic determinants

Energy Technology Data Exchange (ETDEWEB)

Walsh, Simon L.F.; Devaraj, Anand; Hansell, David M. [Royal Brompton Hospital, Department of Radiology, London (United Kingdom); Sverzellati, Nicola [University of Parma, Department of Clinical Sciences, Section of Radiology, Parma (Italy); Wells, Athol U. [Royal Brompton Hospital, Interstitial Lung Diseases Unit, London (United Kingdom)

2012-08-15

To investigate high resolution computed tomography (HRCT) and pulmonary function indices (PFTs) for determining prognosis in patients with chronic fibrotic hypersensitivity pneumonitis (CHP). Case records, PFTs (FEV{sub 1}, FVC and DLco) and HRCTs of ninety-two patients with chronic hypersensitivity pneumonitis were evaluated. HRCT studies were scored by two observers for total disease extent, ground-glass opacification, fine and coarse reticulation, microcystic and macrocystic honeycombing, centrilobular emphysema and consolidation. Traction bronchiectasis within each pattern was graded. Using Cox proportional hazards regression models the prognostic strength of individual HRCT patterns and pulmonary function test variables were determined. There were forty two deaths during the study period. Increasing severity of traction bronchiectasis was the strongest predictor of mortality (HR 1.10, P < 0.001, 95%CI 1.04-1.16). Increasing global interstitial disease extent (HR 1.02, P = 0.02, 95%CI 1.00-1.03), microcystic honeycombing (HR 1.09, P = 0.019, 95%CI 1.01-1.17) and macrocystic honeycombing (HR 1.06, P < 0.01, 95%CI 1.01-1.10) were also independent predictors of mortality. In contrast, no individual PFT variable was predictive of mortality once HRCT patterns were accounted for. HRCT patterns, in particular, severity of traction bronchiectasis and extent of honeycombing are superior to pulmonary function tests for predicting mortality in patients with CHP. (orig.)

High-resolution Computed Tomography Findings of H1N1 Influenza-Associated Pneumonia in Korea

Energy Technology Data Exchange (ETDEWEB)

Lee, Byung Chan; Choi, Song; Kim, Jin Woong; Lim, Hyo Soon [Dept. of Radiology, Chonnam National University Hospital, Chonnam National University School of Medicine, Kwangju (Korea, Republic of); Seon, Hyung Joo; Shin, Sang Soo [Dept. of Radiology, Chonnam National University Hospital, Chonnam National University School of Medicine, Kwangju (Korea, Republic of); Kim, Yun Hyeon; Park, Kyung Hwa [Dept. of Internal Medicine, Chonnam National University Hospital, Chonnam National University School of Medicine, Kwangju (Korea, Republic of)

2011-04-15

To evaluate and compare the high-resolution computed tomography (HRCT) findings of patients with H1N1 influenza-associated pneumonia compared usual community acquired pneumonia (CAP), to determine whether there were any useful common HRCT findings predicting their prognosis. HRCT findings of 31 patients (M:F = 16:15, mean age 42 yrs) with Influenza A (H1N1) infection were retrospectively reviewed for abnormal HRCT findings and compared to HRCT findings of CAP in matched patients. Patients were matched according to age and sex, from 2009 to January 2010. The predominant HRCT findings of pneumonia consisted of areas of consolidation and/or groundglass opacity (GGO) which showed no statistically significant differences when comparing the two groups. However, the abnormalities of H1N1-related pneumonia showed higher bilaterality and multilobar or multisegmental involvement compared with CAP (p < 0.05). Internal low attenuation or air-densities in pulmonary infiltration /or lymphadenopathy was observed only in patients with CAP (p < 0.05). HRCT findings in 8 patients with poor clinical outcome had bilaterality (p=0.015), multilobar, and multisegmental involvement. The predominant HRCT findings of H1N1-related pneumonia were areas of consolidation and/or GGO. In addition, H1N1-related pneumonia showed higher bilaterality or multilobar/multisegmental involvement compared with CAP. The patients who presented bilaterality had a worse clinical outcome.

Breaking the Crowther limit: Combining depth-sectioning and tilt tomography for high-resolution, wide-field 3D reconstructions

Energy Technology Data Exchange (ETDEWEB)

Hovden, Robert, E-mail: rmh244@cornell.edu [School of Applied and Engineering Physics and Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853 (United States); Ercius, Peter [National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Jiang, Yi [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Wang, Deli; Yu, Yingchao; Abruña, Héctor D. [Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853 (United States); Elser, Veit [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Muller, David A. [School of Applied and Engineering Physics and Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY 14853 (United States)

2014-05-01

To date, high-resolution (<1 nm) imaging of extended objects in three-dimensions (3D) has not been possible. A restriction known as the Crowther criterion forces a tradeoff between object size and resolution for 3D reconstructions by tomography. Further, the sub-Angstrom resolution of aberration-corrected electron microscopes is accompanied by a greatly diminished depth of field, causing regions of larger specimens (>6 nm) to appear blurred or missing. Here we demonstrate a three-dimensional imaging method that overcomes both these limits by combining through-focal depth sectioning and traditional tilt-series tomography to reconstruct extended objects, with high-resolution, in all three dimensions. The large convergence angle in aberration corrected instruments now becomes a benefit and not a hindrance to higher quality reconstructions. A through-focal reconstruction over a 390 nm 3D carbon support containing over 100 dealloyed and nanoporous PtCu catalyst particles revealed with sub-nanometer detail the extensive and connected interior pore structure that is created by the dealloying instability. - Highlights: • Develop tomography technique for high-resolution and large field of view. • We combine depth sectioning with traditional tilt tomography. • Through-focal tomography reduces tilts and improves resolution. • Through-focal tomography overcomes the fundamental Crowther limit. • Aberration-corrected becomes a benefit and not a hindrance for tomography.

High-resolution CT of lesions of the optic nerve

International Nuclear Information System (INIS)

Peyster, R.G.; Hoover, E.D.; Hershey, B.L.; Haskin, M.E.

1983-01-01

The optic nerves are well demonstrated by high-resolution computed tomography. Involvement of the optic nerve by optic gliomas and optic nerve sheath meningiomas is well known. However, nonneoplastic processes such as increased intracranial pressure, optic neuritis, Grave ophthalmopathy, and orbital pseudotumor may also alter the appearance of the optic nerve/sheath on computed tomography. Certain clinical and computed tomographic features permit distinction of these nonneoplastic tumefactions from tumors

Can high-resolution peripheral quantitative computed tomography imaging of subchondral and cortical bone predict condylar fracture in Thoroughbred racehorses?

Science.gov (United States)

Trope, G D; Ghasem-Zadeh, A; Anderson, G A; Mackie, E J; Whitton, R C

2015-07-01

High-resolution 3D imaging may improve the prediction and/or early identification of condylar fractures of the distal metacarpus/tarsus and reduce the frequency of breakdown injury in racehorses. To test the hypotheses that horses suffering condylar fractures have higher bone volume fraction (BV/TV) of the distal metacarpal epiphysis, greater subchondral bone thickness at the fracture site and higher second moment of inertia in the metacarpal midshaft as identified with high-resolution 3D imaging. Cross-sectional study using cadaver material. Thoroughbreds that died on racetracks were grouped as: 1) horses with third metacarpal (McIII) fractures with a condylar component (cases, n = 13); 2) horses with no limb fracture (controls, n = 8); 3) horses with fractures in other bones or suspensory apparatus disruption (other fatal injuries, n = 16). The palmar condyles of McIII and the midshaft were examined with high resolution peripheral quantitative computed tomography (HR-pQCT). Statistical analysis included logistic regression and Spearman's correlation. There were no significant differences in BV/TV of distal McIII and second moment of inertia of the midshaft between cases and controls. Epiphyseal bone BV/TV was greater in injured limbs of horses with any fatal limb injury (Groups 1 and 3 combined) compared with controls (odds ratio = 1.20, 95% confidence interval 1.01-1.42, P = 0.034). An epiphyseal BV/TV>0.742 resulted in a sensitivity of 82.8% and specificity of 62.5% in identifying horses with fatal limb injury. In horses without condylar fracture, increased subchondral bone thickness was associated with palmar osteochondral disease lesions in the adjacent condyle (rs = 0.65, Phorses at risk of any fatal breakdown injury but not metacarpal condylar fractures. Measurement of parasagittal groove subchondral bone thickness is complicated by adjacent palmar osteochondral disease lesions. Thus, high-resolution imaging of the distal metacarpus appears to have limited

Clinical use of pulmonary function tests and high-resolution tomography in interstitial lung diseases

International Nuclear Information System (INIS)

Garcia C, Clara P; Mejia M, Luis F

2010-01-01

Diagnosis of interstitial lung diseases is generally arrived at by clinical history, physical examination, and radiologic images, especially high-resolution CT-scanning. It is important to note that, while these diseases have different clinical and histological characteristics, they share a basic pattern of abnormal lung function. With regard to high-resolution tomography, the characteristics of these diseases are similar, although there are specific differences that can be helpful for correct diagnosis. These diseases have severe consequences on respiratory gas exchange. These alterations, combined with other abnormalities of lung function, cause the signs and symptoms and have an impact on quality of life. The use of physiologic parameters is not only helpful for diagnosis, but can also assess severity, help to define the consequences of treatment, and aid in the follow-up. Although some pulmonary function tests can remain completely normal with severe radiographic findings, 10% of patients have impaired lung function before radiologic changes. High-resolution tomography is an essential imaging tool for the study of these patients. This is true not only for diagnosis, but also with regard to clinical parameters and follow-up. Its prognostic use is continually gaining importance. In this article we assess the clinical use of pulmonary function tests and high-resolution tomography in interstitial lung diseases.

A review of X-ray computed axial tomography

International Nuclear Information System (INIS)

Schmidt, M.

1989-01-01

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

Refinement procedure for the image alignment in high-resolution electron tomography.

Science.gov (United States)

Houben, L; Bar Sadan, M

2011-01-01

High-resolution electron tomography from a tilt series of transmission electron microscopy images requires an accurate image alignment procedure in order to maximise the resolution of the tomogram. This is the case in particular for ultra-high resolution where even very small misalignments between individual images can dramatically reduce the fidelity of the resultant reconstruction. A tomographic-reconstruction based and marker-free method is proposed, which uses an iterative optimisation of the tomogram resolution. The method utilises a search algorithm that maximises the contrast in tomogram sub-volumes. Unlike conventional cross-correlation analysis it provides the required correlation over a large tilt angle separation and guarantees a consistent alignment of images for the full range of object tilt angles. An assessment based on experimental reconstructions shows that the marker-free procedure is competitive to the reference of marker-based procedures at lower resolution and yields sub-pixel accuracy even for simulated high-resolution data. Copyright © 2011 Elsevier B.V. All rights reserved.

Utility of high-resolution computed tomography for predicting risk of sputum smear-negative pulmonary tuberculosis

International Nuclear Information System (INIS)

Nakanishi, Masanori; Demura, Yoshiki; Ameshima, Shingo; Kosaka, Nobuyuki; Chiba, Yukio; Nishikawa, Satoshi; Itoh, Harumi; Ishizaki, Takeshi

2010-01-01

Background: To diagnose sputum smear-negative pulmonary tuberculosis (PTB) is difficult and the ability of high-resolution computed tomography (HRCT) for diagnosing PTB has remained unclear in the sputum smear-negative setting. We retrospectively investigated whether or not this imaging modality can predict risk for sputum smear-negative PTB. Methods: We used HRCT to examine the findings of 116 patients with suspected PTB despite negative sputum smears for acid-fast bacilli (AFB). We investigated their clinical features and HRCT-findings to predict the risk for PTB by multivariate analysis and a combination of HRCT findings by stepwise regression analysis. We then designed provisional HRCT diagnostic criteria based on these results to rank the risk of PTB and blinded observers assessed the validity and reliability of these criteria. Results: A positive tuberculin skin test alone among clinical laboratory findings was significantly associated with an increase of risk of PTB. Multivariate regression analysis showed that large nodules, tree-in-bud appearance, lobular consolidation and the main lesion being located in S1, S2, and S6 were significantly associated with an increased risk of PTB. Stepwise regression analysis showed that coexistence of the above 4 factors was most significantly associated with an increase in the risk for PTB. Ranking of the results using our HRCT diagnostic criteria by blinded observers revealed good utility and agreement for predicting PTB risk. Conclusions: Even in the sputum smear-negative setting, HRCT can predict the risk of PTB with good reproducibility and can select patients having a high probability of PTB.

Utility of high-resolution computed tomography for predicting risk of sputum smear-negative pulmonary tuberculosis

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Masanori [Departments of Respiratory Medicine, Faculty of Medical Sciences, University of Fukui, 23 Shimoaizuki Eiheizi-cho, Fukui 910-1193 (Japan)], E-mail: mnakanishi@nifty.ne.jp; Demura, Yoshiki; Ameshima, Shingo [Departments of Respiratory Medicine, Faculty of Medical Sciences, University of Fukui, 23 Shimoaizuki Eiheizi-cho, Fukui 910-1193 (Japan); Kosaka, Nobuyuki [Departments of Radiology, Faculty of Medical Sciences, University of Fukui, 23 Shimoaizuki Eiheizi-cho, Fukui 910-1193 (Japan); Chiba, Yukio [Department of Respiratory Medicine, National Hospital Organization, Fukui Hospital, Tsuruga, Fukui 914-0195 (Japan); Nishikawa, Satoshi [Department of Radiology, National Hospital Organization, Fukui Hospital, Tsuruga, Fukui 914-0195 (Japan); Itoh, Harumi [Departments of Radiology, Faculty of Medical Sciences, University of Fukui, 23 Shimoaizuki Eiheizi-cho, Fukui 910-1193 (Japan); Ishizaki, Takeshi [Departments of Respiratory Medicine, Faculty of Medical Sciences, University of Fukui, 23 Shimoaizuki Eiheizi-cho, Fukui 910-1193 (Japan)

2010-03-15

Background: To diagnose sputum smear-negative pulmonary tuberculosis (PTB) is difficult and the ability of high-resolution computed tomography (HRCT) for diagnosing PTB has remained unclear in the sputum smear-negative setting. We retrospectively investigated whether or not this imaging modality can predict risk for sputum smear-negative PTB. Methods: We used HRCT to examine the findings of 116 patients with suspected PTB despite negative sputum smears for acid-fast bacilli (AFB). We investigated their clinical features and HRCT-findings to predict the risk for PTB by multivariate analysis and a combination of HRCT findings by stepwise regression analysis. We then designed provisional HRCT diagnostic criteria based on these results to rank the risk of PTB and blinded observers assessed the validity and reliability of these criteria. Results: A positive tuberculin skin test alone among clinical laboratory findings was significantly associated with an increase of risk of PTB. Multivariate regression analysis showed that large nodules, tree-in-bud appearance, lobular consolidation and the main lesion being located in S1, S2, and S6 were significantly associated with an increased risk of PTB. Stepwise regression analysis showed that coexistence of the above 4 factors was most significantly associated with an increase in the risk for PTB. Ranking of the results using our HRCT diagnostic criteria by blinded observers revealed good utility and agreement for predicting PTB risk. Conclusions: Even in the sputum smear-negative setting, HRCT can predict the risk of PTB with good reproducibility and can select patients having a high probability of PTB.

High-resolution computed tomography versus chest radiography in the diagnosis of interstitial lung disease in systemic sclerosis

International Nuclear Information System (INIS)

Azevedo, Ana Beatriz Cordeiro de; Calderaro, Debora; Moreira, Caio; Guimaraes, Silvana Mangeon Meirelles; Tavares Junior, Wilson Campos; Leao Filho, Hilton Muniz; Andrade, Diego Correa de; Ferreira, Cid Sergio; Vieira, Jose Nelson Mendes

2005-01-01

Objective: To compare the accuracy of high-resolution computed tomography (HRCT) with chest radiography in the diagnosis of interstitial lung disease in systemic sclerosis (SSc). Materials And Methods: HRCT scans and chest radiographs in postero-anterior and lateral views were performed in 34 patients with systemic sclerosis, according to the American College of Rheumatology preliminary criteria for the diagnosis of SSc. The prevalence of radiological findings suggestive of interstitial lung disease in SSc seen on both imaging methods was compared. Results: Interstitial disease was observed on HRCT images of 31 patients (91%) and in the chest radiographs of 16 patients (47%). The most frequent findings observed on HRCT were septal lines (74%), honeycombing (56%) and parenchymal bands (26%). Chest radiographs showed reticular areas of attenuation in 11 patients (32%) and parenchymal distortion in 12% of the patients. In 18 patients (53%) with normal chest radiographs HRCT showed septal lines in 55%, ground glass in 44%, honeycombing in 38.5% and cysts in 33%. Conclusion: HRCT is more sensitive than chest radiography in the evaluation of incipient interstitial lung involvement in patients with SSc and can provide a justification for immunosuppressive therapy in patients with early disease. (author)

Spectrum of high resolution computed tomography findings in occupational lung disease: experience in a tertiary care institute.

Science.gov (United States)

Bhawna, Satija; Ojha, U C; Kumar, Sanyal; Gupta, Rajiv; Gothi, Dipti; Pal, R S

2013-01-01

To study the spectrum of high resolution computed tomography (HRCT) findings in occupational lung disease in industrial workers and to assess the utility of International classification of HRCT for occupational and environmental respiratory diseases (ICHOERD). Retrospective analysis of radiological data (radiographs and computed tomography chest scans) gathered over a period of 3 years (January 2010- December 2012) of industrial workers in an organised sector who presented with respiratory complaints. The HRCT findings were evaluated using ICHOERD. There were 5 females and 114 males in the study, with a mean age of 49 years. These workers were exposed to different harmful agents including silica, asbestos, cotton dust, metal dust, iron oxide, organic dust, rubber fumes, plastic fumes, acid fumes, and oil fumes. There were 10 smokers in the study. The radiograph of chest was normal in 53 patients. 46% of these normal patients (21.8% of total) demonstrated positive findings on HRCT. When the radiograph was abnormal, HRCT provided more accurate information and excluded the other diagnosis. The HRCT findings were appropriately described using the ICHOERD. Bronchiectasis was the most common finding (44.5%) with mild central cylindrical bronchiectasis as the most common pattern. Pleural thickening was seen in 41 patients (34.5%). Enlarged hilar or mediastinal lymphnodes were seen in 10 patients (8.4%) with egg-shell calcification in 1 patient exposed to silica. Bronchogenic carcinoma was seen in 1 patient exposed to asbestos. Occupational lung disease is a common work related condition in industrial workers even in the organized sector. Though chest radiograph is the primary diagnostic tool, HRCT is the undisputed Gold Standard for evaluation of these patients. Despite the disadvantage of radiation exposure, low dose CT may serve as an important tool for screening and surveillance. The ICHOERD is a powerful and reliable tool not only for diagnosis, but also for

Evaluation of pulmonary changes due to biomass fuels using high-resolution computed tomography

International Nuclear Information System (INIS)

Kara, Mustafa; Tas, Fikret; Bulut, Sema; Akkurt, Ibrahim; Seyfikli, Zehra

2003-01-01

Biomass fuels are frequently used in rural areas of the world for cooking and heating frequently. It has been reported that the use of these fuels causes hazardous effects on the lungs. In this study, we evaluated the pulmonary changes due to the use of biomass fuels in a female population that lives in our territory by high-resolution computed tomography (HRCT). The study analyzed three groups of women. The first group comprised those subjects who were exposed to biomass without respiratory symptoms (group 1; n=32). The second group comprised those individuals that were exposed to biomass and showed respiratory symptoms, such as cough, sputum production, and dyspnea (group 2; n=30). The third group was composed of women who were not exposed to biomass and also had no respiratory symptoms (group 3; n=30). Women with a history of concomitant pulmonary diseases were excluded from the study. All groups were examined with HRCT. Groups 1 and 2 (individuals exposed to biomass fuels) had more pathologic findings than group 3 (not exposed to biomass fuels). Ground-glass appearance was seen in 71.9% in group 1, 23.3% in group 2, and 3.3% in group 3. The difference between the groups was statistically significant (p<0.05). Fibrotic bands were seen 50% in group 1, 63.3% in group 2, and only 6.7% in group 3 (p<0.001). Exposure to biomass fuels was the cause or predisposing factor for many pulmonary diseases, ranging from chronic bronchitis to diffuse lung diseases. We believe that these pathological changes due to biomass fuels can be detected earlier by HRCT and the diseases might be prevented or treated earlier. (orig.)

Improvement in the detection of locoregional recurrence in head and neck malignancies: F-18 fluorodeoxyglucose-positron emission tomography/computed tomography compared to high-resolution contrast-enhanced computed tomography and endoscopic examination.

Science.gov (United States)

Rangaswamy, Balasubramanya; Fardanesh, M Reza; Genden, Eric M; Park, Eunice E; Fatterpekar, Girish; Patel, Zara; Kim, Jongho; Som, Peter M; Kostakoglu, Lale

2013-11-01

To compare the diagnostic efficacy of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG-PET)/computed tomography (CT) to that of contrast-enhanced high-resolution CT (HRCT) and assess the value of a combinatorial approach in detection of recurrent squamous cell cancer of the head and neck (HNC) and to assess the efficacy of FDG-PET/CT with and without HRCT in comparison to standard-of-care follow-up--physical examination (PE) and endoscopy (E)--in determination of locally recurrent HNC. Retrospective study. A total of 103 patients with HNC underwent FDG-PET/CT and neck HRCT. There were two groups of patients: Group A had an FDG-PET study acquired with low-dose CT, and group B had an FDG-PET study acquired with HRCT. The PET data obtained with or without HRCT were compared on a lesion and patient basis with the results of the PE/E. On a lesion basis, both groups combined had higher sensitivity and negative predictive value (NPV) than the HRCT. Specificity and positive predictive value (PPV) for group B were higher than for group A. On a patient basis, both groups combined had a higher sensitivity and NPV than PE/E, respectively, although specificity of PE/E was higher than that of either group. PET data obtained with either protocol directly influenced treatment. HRCT increases the specificity and PPV of PET/CT when acquired simultaneously with PET. FDG-PET/CT acquired with either LDCT or HRCT has higher accuracy than HRCT alone and increases the sensitivity and NPV of PE/E. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Oversampling in the computed tomography measurements applied for bone structure studies as a method of spatial resolution improvement

International Nuclear Information System (INIS)

Tatoń, Grzegorz; Rokita, Eugeniusz; Rok, Tomasz; Beckmann, Felix

2012-01-01

Our purpose was to check the potential ability of oversampling as a method for computed tomography axial resolution improvement. The method of achieving isotropic and fine resolution, when the scanning system is characterized by anisotropic resolutions is proposed. In case of typical clinical system the axial resolution is much lower than the planar one. The idea relies on the scanning with a wide overlapping layers and subsequent resolution recovery on the level of scanning step. Simulated three-dimensional images, as well as the real microtomographic images of rat femoral bone were used in proposed solution tests. Original high resolution images were virtually scanned with a wide beam and a small step in order to simulate the real measurements. The low resolution image series were subsequently processed in order to back to the original fine one. Original, virtually scanned and recovered images resolutions were compared with the use of modulation transfer function (MTF). A good ability of oversampling as a method for the resolution recovery was showed. It was confirmed by comparing the resolving powers after and before resolution recovery. The MTF analysis showed resolution improvement. The resolution improvement was achieved but the image noise raised considerably, which is clearly visible on image histograms. Despite this disadvantage the proposed method can be successfully used in practice, especially in the trabecular bone studies because of high contrast between trabeculae and intertrabecular spaces

Imaging of cellular spread on a three-dimensional scaffold by means of a novel cell-labeling technique for high-resolution computed tomography.

Science.gov (United States)

Thimm, Benjamin W; Hofmann, Sandra; Schneider, Philipp; Carretta, Roberto; Müller, Ralph

2012-03-01

Computed tomography (CT) represents a truly three-dimensional (3D) imaging technique that can provide high-resolution images on the cellular level. Thus, one approach to detect single cells is X-ray absorption-based CT, where cells are labeled with a dense, opaque material providing the required contrast for CT imaging. Within the present work, a novel cell-labeling method has been developed showing the feasibility of labeling fixed cells with iron oxide (FeO) particles for subsequent CT imaging and quantitative morphometry. A biotin-streptavidin detection system was exploited to bind FeO particles to its target endothelial cells. The binding of the particles was predominantly close to the cell centers on 2D surfaces as shown by light microscopy, scanning electron microscopy, and CT. When cells were cultured on porous, 3D polyurethane surfaces, significantly more FeO particles were detected compared with surfaces without cells and FeO particle labeling using CT. Here, we report on the implementation and evaluation of a novel cell detection method based on high-resolution CT. This system has potential in cell tracking for 3D in vitro imaging in the future.

Automatic Identification and Reconstruction of the Right Phrenic Nerve on Computed Tomography

OpenAIRE

Bamps, Kobe; Cuypers, Céline; Polmans, Pieter; Claesen, Luc; Koopman, Pieter

2016-01-01

An automatic computer algorithm was successfully constructed, enabling identification and reconstruction of the right phrenic nerve on high resolution coronary computed tomography scans. This could lead to a substantial reduction in the incidence of phrenic nerve paralysis during pulmonary vein isolation using ballon techniques.

Preliminary frequency-domain analysis for the reconstructed spatial resolution of muon tomography

Science.gov (United States)

Yu, B.; Zhao, Z.; Wang, X.; Wang, Y.; Wu, D.; Zeng, Z.; Zeng, M.; Yi, H.; Luo, Z.; Yue, X.; Cheng, J.

2014-11-01

Muon tomography is an advanced technology to non-destructively detect high atomic number materials. It exploits the multiple Coulomb scattering information of muon to reconstruct the scattering density image of the traversed object. Because of the statistics of muon scattering, the measurement error of system and the data incompleteness, the reconstruction is always accompanied with a certain level of interference, which will influence the reconstructed spatial resolution. While statistical noises can be reduced by extending the measuring time, system parameters determine the ultimate spatial resolution that one system can reach. In this paper, an effective frequency-domain model is proposed to analyze the reconstructed spatial resolution of muon tomography. The proposed method modifies the resolution analysis in conventional computed tomography (CT) to fit the different imaging mechanism in muon scattering tomography. The measured scattering information is described in frequency domain, then a relationship between the measurements and the original image is proposed in Fourier domain, which is named as "Muon Central Slice Theorem". Furthermore, a preliminary analytical expression of the ultimate reconstructed spatial is derived, and the simulations are performed for validation. While the method is able to predict the ultimate spatial resolution of a given system, it can also be utilized for the optimization of system design and construction.

Preliminary frequency-domain analysis for the reconstructed spatial resolution of muon tomography

International Nuclear Information System (INIS)

Yu, B.; Zhao, Z.; Wang, X.; Wang, Y.; Wu, D.; Zeng, Z.; Zeng, M.; Yi, H.; Luo, Z.; Yue, X.; Cheng, J.

2014-01-01

Muon tomography is an advanced technology to non-destructively detect high atomic number materials. It exploits the multiple Coulomb scattering information of muon to reconstruct the scattering density image of the traversed object. Because of the statistics of muon scattering, the measurement error of system and the data incompleteness, the reconstruction is always accompanied with a certain level of interference, which will influence the reconstructed spatial resolution. While statistical noises can be reduced by extending the measuring time, system parameters determine the ultimate spatial resolution that one system can reach. In this paper, an effective frequency-domain model is proposed to analyze the reconstructed spatial resolution of muon tomography. The proposed method modifies the resolution analysis in conventional computed tomography (CT) to fit the different imaging mechanism in muon scattering tomography. The measured scattering information is described in frequency domain, then a relationship between the measurements and the original image is proposed in Fourier domain, which is named as M uon Central Slice Theorem . Furthermore, a preliminary analytical expression of the ultimate reconstructed spatial is derived, and the simulations are performed for validation. While the method is able to predict the ultimate spatial resolution of a given system, it can also be utilized for the optimization of system design and construction

Proton computed tomography

International Nuclear Information System (INIS)

Hanson, K.M.

1978-01-01

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

High resolution IVEM tomography of biological specimens

Energy Technology Data Exchange (ETDEWEB)

Sedat, J.W.; Agard, D.A. [Univ. of California, San Francisco, CA (United States)

1997-02-01

Electron tomography is a powerful tool for elucidating the three-dimensional architecture of large biological complexes and subcellular organelles. The introduction of intermediate voltage electron microscopes further extended the technique by providing the means to examine very large and non-symmetrical subcellular organelles, at resolutions beyond what would be possible using light microscopy. Recent studies using electron tomography on a variety of cellular organelles and assemblies such as centrosomes, kinetochores, and chromatin have clearly demonstrated the power of this technique for obtaining 3D structural information on non-symmetric cell components. When combined with biochemical and molecular observations, these 3D reconstructions have provided significant new insights into biological function.

Cochlear Implant Electrode Localization Using an Ultra-High Resolution Scan Mode on Conventional 64-Slice and New Generation 192-Slice Multi-Detector Computed Tomography.

Science.gov (United States)

Carlson, Matthew L; Leng, Shuai; Diehn, Felix E; Witte, Robert J; Krecke, Karl N; Grimes, Josh; Koeller, Kelly K; Bruesewitz, Michael R; McCollough, Cynthia H; Lane, John I

2017-08-01

A new generation 192-slice multi-detector computed tomography (MDCT) clinical scanner provides enhanced image quality and superior electrode localization over conventional MDCT. Currently, accurate and reliable cochlear implant electrode localization using conventional MDCT scanners remains elusive. Eight fresh-frozen cadaveric temporal bones were implanted with full-length cochlear implant electrodes. Specimens were subsequently scanned with conventional 64-slice and new generation 192-slice MDCT scanners utilizing ultra-high resolution modes. Additionally, all specimens were scanned with micro-CT to provide a reference criterion for electrode position. Images were reconstructed according to routine temporal bone clinical protocols. Three neuroradiologists, blinded to scanner type, reviewed images independently to assess resolution of individual electrodes, scalar localization, and severity of image artifact. Serving as the reference standard, micro-CT identified scalar crossover in one specimen; imaging of all remaining cochleae demonstrated complete scala tympani insertions. The 192-slice MDCT scanner exhibited improved resolution of individual electrodes (p implant imaging compared with conventional MDCT. This technology provides important feedback regarding electrode position and course, which may help in future optimization of surgical technique and electrode design.

Technical aspects of X-ray micro-computed tomography. Initial experience of 27-μm resolution using feldkamp cone-beam reconstruction

International Nuclear Information System (INIS)

Yamamoto, Shuji; Suzuki, Masahiro; Kohara, Kazushi; Iinuma, Gen; Moriyama, Noriyuki

2007-01-01

The objective of this study was to introduce the technical utility of micro-computed tomography (CT) with 27-μm resolution by cone-beam CT algorithm. Whole-body micro-CT scans were performed to honeybee. Two- and three-dimensional image analyses were performed by originally developed and available open-source software for acquired images. The original contribution of this work is to describe the technical characteristics of the X-ray micro-CT system, keeping a small experimental insect in a unique condition. Micro-CT may be used as a rapid prototyping tool to research and understand the high-resolution system with Feldkamp cone-beam reconstruction. (author)

Scaling law for noise variance and spatial resolution in differential phase contrast computed tomography

International Nuclear Information System (INIS)

Chen Guanghong; Zambelli, Joseph; Li Ke; Bevins, Nicholas; Qi Zhihua

2011-01-01

Purpose: The noise variance versus spatial resolution relationship in differential phase contrast (DPC) projection imaging and computed tomography (CT) are derived and compared to conventional absorption-based x-ray projection imaging and CT. Methods: The scaling law for DPC-CT is theoretically derived and subsequently validated with phantom results from an experimental Talbot-Lau interferometer system. Results: For the DPC imaging method, the noise variance in the differential projection images follows the same inverse-square law with spatial resolution as in conventional absorption-based x-ray imaging projections. However, both in theory and experimental results, in DPC-CT the noise variance scales with spatial resolution following an inverse linear relationship with fixed slice thickness. Conclusions: The scaling law in DPC-CT implies a lesser noise, and therefore dose, penalty for moving to higher spatial resolutions when compared to conventional absorption-based CT in order to maintain the same contrast-to-noise ratio.

COST EFFECTIVE AND HIGH RESOLUTION SUBSURFACE CHARACTERIZATION USING HYDRAULIC TOMOGRAPHY

Science.gov (United States)

2017-08-01

objective of this project is to provide the DoD and its remediation contractors with the HT technology for delineating the spatial distribution of...STATEMENT Approved for public release; distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Hydraulic Tomography ( HT ) is a high-resolution...performance of subsurface remedial actions at environmental sites. The good technical performance and cost-effectiveness of HT have been demonstrated in

High speed computer assisted tomography

International Nuclear Information System (INIS)

Maydan, D.; Shepp, L.A.

1980-01-01

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

Improvement of resolution in full-view linear-array photoacoustic computed tomography using a novel adaptive weighting method

Science.gov (United States)

Omidi, Parsa; Diop, Mamadou; Carson, Jeffrey; Nasiriavanaki, Mohammadreza

2017-03-01

Linear-array-based photoacoustic computed tomography is a popular methodology for deep and high resolution imaging. However, issues such as phase aberration, side-lobe effects, and propagation limitations deteriorate the resolution. The effect of phase aberration due to acoustic attenuation and constant assumption of the speed of sound (SoS) can be reduced by applying an adaptive weighting method such as the coherence factor (CF). Utilizing an adaptive beamforming algorithm such as the minimum variance (MV) can improve the resolution at the focal point by eliminating the side-lobes. Moreover, invisibility of directional objects emitting parallel to the detection plane, such as vessels and other absorbing structures stretched in the direction perpendicular to the detection plane can degrade resolution. In this study, we propose a full-view array level weighting algorithm in which different weighs are assigned to different positions of the linear array based on an orientation algorithm which uses the histogram of oriented gradient (HOG). Simulation results obtained from a synthetic phantom show the superior performance of the proposed method over the existing reconstruction methods.

Illustrated computer tomography

International Nuclear Information System (INIS)

Takahashi, S.

1983-01-01

This book provides the following information: basic aspects of computed tomography; atlas of computed tomography of the normal adult; clinical application of computed tomography; and radiotherapy planning and computed tomography

[CONE BEAM COMPUTED TOMOGRAPHY IN DIAGNOSTICS OF ODONTOGENIC MAXILLARY SINUSITIS (CASE REPORTS)].

Science.gov (United States)

Demidova, E; Khurdzidze, G

2017-06-01

Diagnostic studies performed by cone beam computed tomography Morita 3D made possible to obtain high resolution images of hard tissues of upper jawbone and maxillary sinus, to detect bony tissue defects, such as odontogenic cysts, cystogranulomas and granulomas. High-resolution and three dimensional tomographic image reconstructions allowed for optimal and prompt determination of the scope of surgical treatment and planning of effective conservative treatment regimen. Interactive diagnostics helped to estimate cosmetic and functional results of surgical treatment, to prevent the occurrence of surgical complications, and to evaluate the efficacy of conservative treatment. The obtained data contributed to determination of particular applications of cone beam computed tomography in the diagnosis of odontogenic maxillary sinusitis, detection of specific defects with cone beam tomography as the most informative method of diagnosis; as well as to determination of weak and strong sides, and helped to offer mechanisms of x-ray diagnostics to dental surgeons and ENT specialists.

Computed Tomography Status

Science.gov (United States)

Hansche, B. D.

1983-01-01

Computed tomography (CT) is a relatively new radiographic technique which has become widely used in the medical field, where it is better known as computerized axial tomographic (CAT) scanning. This technique is also being adopted by the industrial radiographic community, although the greater range of densities, variation in samples sizes, plus possible requirement for finer resolution make it difficult to duplicate the excellent results that the medical scanners have achieved.

Active disease and residual damage in treated Wegener's granulomatosis: an observational study using pulmonary high-resolution computed tomography

International Nuclear Information System (INIS)

Komocsi, Andras; Reuter, Michael; Heller, Martin; Murakoezi, Henriette; Gross, Wolfgang L.; Schnabel, Armin

2003-01-01

The purpose of this study was to determine to what extent high-resolution computed tomography (HRCT) of the lungs can distinguish active inflammatory disease from inactive cicatricial disease in patients treated for Wegener's granulomatosis (WG). Twenty-eight WG patients with active pulmonary disease underwent a first HRCT examination immediately before standard immunosuppressive treatment and a second examination after clinical remission had been achieved. Lesions remaining after treatment were categorized as residual damage and were compared with findings during active disease to see by what features active and cicatricial disease can be distinguished. During active disease 17 patients had nodules/masses, 12 had ground-glass opacities, 6 had septal lines and 6 had non-septal lines. After treatment, ground-glass opacities had resolved completely. Nodules/masses had resolved in 8 patients and had diminished in 7 patients. Residual nodules were distinguished from nodules/masses in active disease by lack of cavitation and a diameter of mostly <15 mm. In one-third of patients lines resolved, but in 8 instances new lines evolved during immunosuppression. During a follow-up period of a median 26.5 months (range 20.0-33.8), patients with residual nodules or lines had no more relapses than patients with completely cleared lungs. Treated pulmonary WG leaves substantial residual damage. High-resolution CT does assist in the distinction between active and inactive lesions. Ground-glass opacities, cavitating nodules/masses and masses measuring more than 3 cm represent active disease ordinarily. Non-cavitary small nodules and septal or non-septal lines can be either active or cicatricial lesions. The nature of these lesions needs to be clarified by longitudinal observation. (orig.)

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)

Accelerated high-resolution photoacoustic tomography via compressed sensing

Science.gov (United States)

Arridge, Simon; Beard, Paul; Betcke, Marta; Cox, Ben; Huynh, Nam; Lucka, Felix; Ogunlade, Olumide; Zhang, Edward

2016-12-01

Current 3D photoacoustic tomography (PAT) systems offer either high image quality or high frame rates but are not able to deliver high spatial and temporal resolution simultaneously, which limits their ability to image dynamic processes in living tissue (4D PAT). A particular example is the planar Fabry-Pérot (FP) photoacoustic scanner, which yields high-resolution 3D images but takes several minutes to sequentially map the incident photoacoustic field on the 2D sensor plane, point-by-point. However, as the spatio-temporal complexity of many absorbing tissue structures is rather low, the data recorded in such a conventional, regularly sampled fashion is often highly redundant. We demonstrate that combining model-based, variational image reconstruction methods using spatial sparsity constraints with the development of novel PAT acquisition systems capable of sub-sampling the acoustic wave field can dramatically increase the acquisition speed while maintaining a good spatial resolution: first, we describe and model two general spatial sub-sampling schemes. Then, we discuss how to implement them using the FP interferometer and demonstrate the potential of these novel compressed sensing PAT devices through simulated data from a realistic numerical phantom and through measured data from a dynamic experimental phantom as well as from in vivo experiments. Our results show that images with good spatial resolution and contrast can be obtained from highly sub-sampled PAT data if variational image reconstruction techniques that describe the tissues structures with suitable sparsity-constraints are used. In particular, we examine the use of total variation (TV) regularization enhanced by Bregman iterations. These novel reconstruction strategies offer new opportunities to dramatically increase the acquisition speed of photoacoustic scanners that employ point-by-point sequential scanning as well as reducing the channel count of parallelized schemes that use detector arrays.

Computed tomography of craniomandibular osteopathy in a dog

International Nuclear Information System (INIS)

Hudson, J.A.; Montgomery, R.D.; Hathcock, J.T.; Jarboe, J.M.

1994-01-01

This report describes the use of computed tomography (CT) to evaluate the tympanic bullae and angular processes of the mandible in a West Highland White Terrier with craniomandibular osteopathy. The patient presented initially for swelling of the right forelimb. The report illustrates the use of computed tomography for evaluation of craniomandibular osteopathy, initial presentation with long-bone pathology, and remarkable resolution of osseous changes

Functional high-resolution computed tomography of pulmonary vascular and airway reactions. Experimental results. Funktionelle HR-CT der Lunge. Experimentelle Untersuchungen pulmonaler Gefaess- und Atemwegsreaktionen

Energy Technology Data Exchange (ETDEWEB)

Herold, C.J. (Universitaetsklinik fuer Radiodiagnostik, Vienna (Austria) Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Radiology); Brown, R.H. (Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Radiology Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Anesthesiology and Intensive Care Medicine Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Physiology); Wetzel, R.C.; Herold, S.M. (Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Anesthesiology and Intensive Care Medicine); Zeerhouni, E.A. (Johns Hopkins Medical Institutions, Baltimore, MD (United States). Dept. of Radiology)

1993-03-01

We describe the use of high-resolution computed tomography (HRCT) for assessment of the function of pulmonary vessels and airways. With its excellent spatial resolution, HRCT is able to demonstrate pulmonary structures as small as 300 [mu]m and can be used to monitor changes following various stimuli. HRCT also provides information about structures smaller than 300 [mu]m through measurement of parenchymal background density. To date, sequential, spiral and ultrafast HRCT techniques have been used in a variety of challenges to gather information about the anatomical correlates of traditional physiological measurements, thus making anatomical-physiological correlation possible. HRCT of bronchial reactivity can demonstrate the location and time course of aerosol-induced broncho-constriction and may show changes not apparent on spirometry. HRCT of the pulmonary vascular system visualized adaptations of vessels during hypoxia and intravascular volume loading and elucidates cardiorespiratory interactions. Experimental studies provide a basis for potential clinical applications of this method. (orig.).

Computed tomography and/or ventriculography

International Nuclear Information System (INIS)

Wende, S.; Kishikawa, T.; Huewel, N.; Kazner, E.; Grumme, T.; Lanksch, W.

1982-01-01

It is discussed if in intracranial tumors, especially in tumors of the posterior cranial fossa, a CT and/or a ventriculography should be practiced. We have made investigations of 134 patients, 93 of whom were children up to 14 years of age. Each case was undertaken computed tomography as well as ventriculography. The results are clearly demonstrating the superiority of computed tomography compared with ventriculography. Ventriculography is a surgical intervention stressing the patients, side-effects may occur, and sometimes serious complications are caused. Modern computed tomography is producing pictures of high quality, which are highly sufficient for neurosurgical intervention. Very rarely additional angiography has to be performed. The diagnosis of intracranial tumors can fully be established by computed tomography, whereas ventriculography is no longer necessary. (orig.) [de

'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

Micro-computed tomography pore-scale study of flow in porous media: Effect of voxel resolution

Science.gov (United States)

Shah, S. M.; Gray, F.; Crawshaw, J. P.; Boek, E. S.

2016-09-01

A fundamental understanding of flow in porous media at the pore-scale is necessary to be able to upscale average displacement processes from core to reservoir scale. The study of fluid flow in porous media at the pore-scale consists of two key procedures: Imaging - reconstruction of three-dimensional (3D) pore space images; and modelling such as with single and two-phase flow simulations with Lattice-Boltzmann (LB) or Pore-Network (PN) Modelling. Here we analyse pore-scale results to predict petrophysical properties such as porosity, single-phase permeability and multi-phase properties at different length scales. The fundamental issue is to understand the image resolution dependency of transport properties, in order to up-scale the flow physics from pore to core scale. In this work, we use a high resolution micro-computed tomography (micro-CT) scanner to image and reconstruct three dimensional pore-scale images of five sandstones (Bentheimer, Berea, Clashach, Doddington and Stainton) and five complex carbonates (Ketton, Estaillades, Middle Eastern sample 3, Middle Eastern sample 5 and Indiana Limestone 1) at four different voxel resolutions (4.4 μm, 6.2 μm, 8.3 μm and 10.2 μm), scanning the same physical field of view. Implementing three phase segmentation (macro-pore phase, intermediate phase and grain phase) on pore-scale images helps to understand the importance of connected macro-porosity in the fluid flow for the samples studied. We then compute the petrophysical properties for all the samples using PN and LB simulations in order to study the influence of voxel resolution on petrophysical properties. We then introduce a numerical coarsening scheme which is used to coarsen a high voxel resolution image (4.4 μm) to lower resolutions (6.2 μm, 8.3 μm and 10.2 μm) and study the impact of coarsening data on macroscopic and multi-phase properties. Numerical coarsening of high resolution data is found to be superior to using a lower resolution scan because it

Influence of the Pixel Sizes of Reference Computed Tomography on Single-photon Emission Computed Tomography Image Reconstruction Using Conjugate-gradient Algorithm.

Science.gov (United States)

Okuda, Kyohei; Sakimoto, Shota; Fujii, Susumu; Ida, Tomonobu; Moriyama, Shigeru

The frame-of-reference using computed-tomography (CT) coordinate system on single-photon emission computed tomography (SPECT) reconstruction is one of the advanced characteristics of the xSPECT reconstruction system. The aim of this study was to reveal the influence of the high-resolution frame-of-reference on the xSPECT reconstruction. 99m Tc line-source phantom and National Electrical Manufacturers Association (NEMA) image quality phantom were scanned using the SPECT/CT system. xSPECT reconstructions were performed with the reference CT images in different sizes of the display field-of-view (DFOV) and pixel. The pixel sizes of the reconstructed xSPECT images were close to 2.4 mm, which is acquired as originally projection data, even if the reference CT resolution was varied. The full width at half maximum (FWHM) of the line-source, absolute recovery coefficient, and background variability of image quality phantom were independent on the sizes of DFOV in the reference CT images. The results of this study revealed that the image quality of the reconstructed xSPECT images is not influenced by the resolution of frame-of-reference on SPECT reconstruction.

Spectrum of High Resolution Computed Tomography Findings in Occupational Lung Disease: Experience in a Tertiary Care Institute

Directory of Open Access Journals (Sweden)

Satija Bhawna

2013-01-01

Full Text Available Objective: To study the spectrum of high resolution computed tomography (HRCT findings in occupational lung disease in industrial workers and to assess the utility of International classification of HRCT for occupational and environmental respiratory diseases (ICHOERD. Materials and Methods: Retrospective analysis of radiological data (radiographs and computed tomography chest scans gathered over a period of 3 years (January 2010- December 2012 of industrial workers in an organised sector who presented with respiratory complaints. The HRCT findings were evaluated using ICHOERD. Results: There were 5 females and 114 males in the study, with a mean age of 49 years. These workers were exposed to different harmful agents including silica, asbestos, cotton dust, metal dust, iron oxide, organic dust, rubber fumes, plastic fumes, acid fumes, and oil fumes. There were 10 smokers in the study. The radiograph of chest was normal in 53 patients. 46% of these normal patients (21.8% of total demonstrated positive findings on HRCT. When the radiograph was abnormal, HRCT provided more accurate information and excluded the other diagnosis. The HRCT findings were appropriately described using the ICHOERD. Bronchiectasis was the most common finding (44.5% with mild central cylindrical bronchiectasis as the most common pattern. Pleural thickening was seen in 41 patients (34.5%. Enlarged hilar or mediastinal lymphnodes were seen in 10 patients (8.4% with egg-shell calcification in 1 patient exposed to silica. Bronchogenic carcinoma was seen in 1 patient exposed to asbestos. Conclusions: Occupational lung disease is a common work related condition in industrial workers even in the organized sector. Though chest radiograph is the primary diagnostic tool, HRCT is the undisputed Gold Standard for evaluation of these patients. Despite the disadvantage of radiation exposure, low dose CT may serve as an important tool for screening and surveillance. The ICHOERD is a

Determination of the activity of pulmonary tuberculosis : the utility of high-resolution computed tomography

International Nuclear Information System (INIS)

Chung, Myung Hee; Lee, Hae Giu; Yu, Won Jong; Chung, Hong Jun; Yang, Bo Sung; Kwon, Soon Suck; Park, Seog Hee

2000-01-01

To evaluate the utility of high-resolution computed tomography (HRCT), as used to determine the activity of tuberculosis, and to analyze the HRCT findings in active and in inactive tuberculosis. We analyzed the HRCT findings of 100 patients (54 men, 46 women; average age, 54 years) who according to the results of chest radiography had pulmonary tuberculosis of undetermined activity. We assessed HRCT findings such as the presence of a centrilobular, macro-, or micronodule; consolidation, ground-glass opacity, cavity, interlobular septal thickening, irregular linear opacities, bronchial wall thickening, bronchovascular bundle distortion, bronchiectasis, atelectasis, and pericicatrical emphysema. We compared the ratio of the area of nodule and consolidation to that of whole lung, and compared the findings between active and inactive tuberculosis. Eleven of 100 patients were excluded because the final diagnosis was other than tuberculosis. In 59 patients, the presence of active pulmonary tuberculosis was proven by positive sputum smear and/or culture for mycobacterium tuberculosis. On the basis of the negative results of these tests, pulmonary tuberculosis was found to be inactive in 30 patients; serial chest radiographs indicated that their condition remained stable over a 6-month period. For HRCT, sensitivity was 96.6%, specificity 56.7%, positive predictive value 81.4%, negative predictive value 89.5%, and accuracy 83.1%. For active tuberculosis, the presence of centrilobular nodules, tree-in-bud, macronodules, cavity within the nodule, and consolidations was statistically significant, while for inactive tuberculosis, that of irregular linear opacities, micronodules, bronchiectasis, and cicatrization atectasis was similarly significant. The CT score for the area of nodules and consolidations was higher in active than in inactive tuberculosis, but only the nodule score showed statistical significance. HRCT can be a useful diagnostic tool for evaluating the activity

Quantified measurement of brain blood volume: comparative evaluations between the single photon emission computer tomography and the positron computer tomography

International Nuclear Information System (INIS)

Bouvard, G.; Fernandez, Y.; Petit-Taboue, M.C.; Derlon, J.M.; Travere, J.M.; Le Poec, C.

1991-01-01

The quantified measurement of cerebral blood volume is interesting for the brain blood circulation studies. This measurement is often used in positron computed tomography. It's more difficult in single photon emission computed tomography: there are physical problems with the limited resolution of the detector, the Compton effect and the photon attenuation. The objectif of this study is to compare the results between these two techniques. The quantified measurement of brain blood volume is possible with the single photon emission computer tomogragry. However, there is a loss of contrast [fr

Detector response restoration in image reconstruction of high resolution positron emission tomography

International Nuclear Information System (INIS)

Liang, Z.

1994-01-01

A mathematical method was studied to model the detector response of high spatial-resolution positron emission tomography systems consisting of close-packed small crystals, and to restore the resolution deteriorated due to crystal penetration and/or nonuniform sampling across the field-of-view (FOV). The simulated detector system had 600 bismuth germanate crystals of 3.14 mm width and 30 mm length packed on a single ring of 60 cm diameter. The space between crystal was filled up with lead. Each crystal was in coincidence with 200 opposite crystals so that the FOV had a radius of 30 cm. The detector response was modeled based on the attenuating properties of the crystals and the septa, as well as the geometry of the detector system. The modeled detector-response function was used to restore the projections from the sinogram of the ring-detector system. The restored projections had a uniform sampling of 1.57 mm across the FOV. The crystal penetration and/or the nonuniform sampling were compensated in the projections. A penalized maximum-likelihood algorithm was employed to accomplish the restoration. The restored projections were then filtered and backprojected to reconstruct the image. A chest phantom with a few small circular ''cold'' objects located at the center and near the periphery of FOV was computer generated and used to test the restoration. The reconstructed images from the restored projections demonstrated resolution improvement off the FOV center, while preserving the resolution near the center

Bronchiolitis obliterans following exposure to sulfur mustard: chest high resolution computed tomography

Energy Technology Data Exchange (ETDEWEB)

Ghanei, Mostafa E-mail: m.ghanei@bmsu.ac.ir; Mokhtari, Majid; Mohammad, Mehdi Mir; Aslani, Jafar

2004-11-01

Background: Pulmonary complications are known to occur in over half of the patients exposed to sulfur mustard (SM). Chemical weapons of mass destruction (WMD) including SM were used by Iraq during Iran-Iraq war between 1983 and 1989. We undertook this study to evaluate the chest high resolution computerized tomography (HRCT) as a diagnostic tool in patients with documented exposure to SM and chronic respiratory symptoms. Method: The medical records of 155 patients exposed to SM during Iran-Iraq war and suffered respiratory complications were reviewed. Chest HRCTs of these patients were examined. Ten healthy controls with no history of exposure to HD were matched for age, gender, and chest HRCT protocol applied. Results: Fifty chest HRCTs of these patients were randomly selected for this study. The most frequent findings were; air trapping 38 (76%), bronchiectasis 37 (74%), mosaic parenchymal attenuation (MPA) 36 (72%), irregular and dilated major airways 33 (66%) bronchial wall thickening (BWT) 45 (90%), and interlobular septal wall thickening (SWT) 13 (26%), respectively. Air trapping in one patient (10%) was the only positive finding in the control group. Conclusions: Chest HRCT findings of bronchiectasis, air trapping, MPA, SWT, and BWT were seen in our patients 15 years after exposure to HD. These findings suggest the diagnosis of bronchiolitis obliterans (BO). We did not encounter chest HRCT features consistent with pulmonary fibrosis.

Computational adaptive optics for broadband optical interferometric tomography of biological tissue.

Science.gov (United States)

Adie, Steven G; Graf, Benedikt W; Ahmad, Adeel; Carney, P Scott; Boppart, Stephen A

2012-05-08

Aberrations in optical microscopy reduce image resolution and contrast, and can limit imaging depth when focusing into biological samples. Static correction of aberrations may be achieved through appropriate lens design, but this approach does not offer the flexibility of simultaneously correcting aberrations for all imaging depths, nor the adaptability to correct for sample-specific aberrations for high-quality tomographic optical imaging. Incorporation of adaptive optics (AO) methods have demonstrated considerable improvement in optical image contrast and resolution in noninterferometric microscopy techniques, as well as in optical coherence tomography. Here we present a method to correct aberrations in a tomogram rather than the beam of a broadband optical interferometry system. Based on Fourier optics principles, we correct aberrations of a virtual pupil using Zernike polynomials. When used in conjunction with the computed imaging method interferometric synthetic aperture microscopy, this computational AO enables object reconstruction (within the single scattering limit) with ideal focal-plane resolution at all depths. Tomographic reconstructions of tissue phantoms containing subresolution titanium-dioxide particles and of ex vivo rat lung tissue demonstrate aberration correction in datasets acquired with a highly astigmatic illumination beam. These results also demonstrate that imaging with an aberrated astigmatic beam provides the advantage of a more uniform depth-dependent signal compared to imaging with a standard gaussian beam. With further work, computational AO could enable the replacement of complicated and expensive optical hardware components with algorithms implemented on a standard desktop computer, making high-resolution 3D interferometric tomography accessible to a wider group of users and nonspecialists.

Positron emission tomography/computed tomography surveillance in patients with Hodgkin lymphoma in first remission has a low positive predictive value and high costs.

Science.gov (United States)

El-Galaly, Tarec Christoffer; Mylam, Karen Juul; Brown, Peter; Specht, Lena; Christiansen, Ilse; Munksgaard, Lars; Johnsen, Hans Erik; Loft, Annika; Bukh, Anne; Iyer, Victor; Nielsen, Anne Lerberg; Hutchings, Martin

2012-06-01

The value of performing post-therapy routine surveillance imaging in patients with Hodgkin lymphoma is controversial. This study evaluates the utility of positron emission tomography/computed tomography using 2-[18F]fluoro-2-deoxyglucose for this purpose and in situations with suspected lymphoma relapse. We conducted a multicenter retrospective study. Patients with newly diagnosed Hodgkin lymphoma achieving at least a partial remission on first-line therapy were eligible if they received positron emission tomography/computed tomography surveillance during follow-up. Two types of imaging surveillance were analyzed: "routine" when patients showed no signs of relapse at referral to positron emission tomography/computed tomography, and "clinically indicated" when recurrence was suspected. A total of 211 routine and 88 clinically indicated positron emission tomography/computed tomography studies were performed in 161 patients. In ten of 22 patients with recurrence of Hodgkin lymphoma, routine imaging surveillance was the primary tool for the diagnosis of the relapse. Extranodal disease, interim positron emission tomography-positive lesions and positron emission tomography activity at response evaluation were all associated with a positron emission tomography/computed tomography-diagnosed preclinical relapse. The true positive rates of routine and clinically indicated imaging were 5% and 13%, respectively (P = 0.02). The overall positive predictive value and negative predictive value of positron emission tomography/computed tomography were 28% and 100%, respectively. The estimated cost per routine imaging diagnosed relapse was US$ 50,778. Negative positron emission tomography/computed tomography reliably rules out a relapse. The high false positive rate is, however, an important limitation and a confirmatory biopsy is mandatory for the diagnosis of a relapse. With no proven survival benefit for patients with a pre-clinically diagnosed relapse, the high costs and low

Basic technological aspects and optimization problems in X-ray computed tomography (C.T.)

International Nuclear Information System (INIS)

Allemand, R.

1987-01-01

The current status and future prospects of physical performance are analysed and the optimization problems are approached for X-ray computed tomography. It is concluded that as long as clinical interest in computed tomography continues, technical advances can be expected in the near future to improve the density resolution, the spatial resolution and the X-ray exposure time. (Auth.)

Crazy-paving sign in high-resolution computed tomography in parainfluenza virus pneumonia

Energy Technology Data Exchange (ETDEWEB)

Matsuno, Osamu [Department of Respiratory Disease, NHO National Osaka Minami Medical Center, Kido higashi machi 2-1, Kawachinagano City, Osaka 586-8521 (Japan)], E-mail: matsuno@ommc-hp.jp; Hayama, Yoshitomo; Honda, Hidehiro; Yamane, Hiroyuki; Yamamoto, Suguru; Ueno, Kiyonobu [Department of Respiratory Disease, NHO National Osaka Minami Medical Center, Kido higashi machi 2-1, Kawachinagano City, Osaka 586-8521 (Japan); Saeki, Yukihiko [Department of Clinical Research, NHO National Osaka Minami Medical Center, Kido higashi machi 2-1, Kawachinagano city, Osaka 586-8521 (Japan)

2010-05-15

The crazy-paving sign is the appearance of a smooth linear pattern superimposed on an area of ground-glass opacity on thin-section computed tomography (CT). A 69-year-old woman was admitted to our hospital for treatment of pneumonia. Thoracic CT showed a crazy-paving sign in the right lung field on admission. She received ceftriaxone and clarithromycin, and the symptoms and infiltration shadow promptly disappeared. Serologic testing revealed a greater than 4-fold increase in the IgG titer for parainfluenza virus I. To our knowledge, there is no previous report of the crazy-paving sign in associated with viral pneumonia in a non-immunocompromised host or with parainfluenza pneumonia.

MSCT versus CBCT: evaluation of high-resolution acquisition modes for dento-maxillary and skull-base imaging

Energy Technology Data Exchange (ETDEWEB)

Dillenseger, Jean-Philippe; Goetz, Christian [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Universite de Strasbourg, Icube, equipe MMB, CNRS, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Matern, Jean-Francois [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Gros, Catherine-Isabelle; Bornert, Fabien [Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Universite de Strasbourg, Faculte de Chirurgie Dentaire, Strasbourg (France); Le Minor, Jean-Marie [Universite de Strasbourg, Icube, equipe MMB, CNRS, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Universite de Strasbourg, Institut d' Anatomie Normale, Strasbourg (France); Constantinesco, Andre [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Choquet, Philippe [Hopitaux Universitaires de Strasbourg, Imagerie Preclinique-UF6237, Pole d' imagerie, Strasbourg (France); Universite de Strasbourg, Icube, equipe MMB, CNRS, Strasbourg (France); Universite de Strasbourg, Federation de Medecine Translationnelle de Strasbourg, Faculte de Medecine, Strasbourg (France); Hopital de Hautepierre, Imagerie Preclinique, Biophysique et Medecine Nucleaire, Strasbourg Cedex (France)

2014-09-24

Our aim was to conduct a quantitative and qualitative evaluation of high-resolution skull-bone imaging for dentistry and otolaryngology using different architectures of recent X-ray computed tomography systems. Three multi-slice computed tomography (MSCT) systems and one Cone-beam computed tomography (CBCT) system were used in this study. All apparatuses were tested with installed acquisition modes and proprietary reconstruction software enabling high-resolution bone imaging. Quantitative analyses were performed with small fields of view with the preclinical vmCT phantom, which permits to measure spatial resolution, geometrical accuracy, linearity and homogeneity. Ten operators performed visual qualitative analyses on the vmCT phantom images, and on dry human skull images. Quantitative analysis showed no significant differences between protocols in terms of linearity and geometric accuracy. All MSCT systems present a better homogeneity than the CBCT. Both quantitative and visual analyses demonstrate that CBCT acquisitions are not better than the collimated helical MSCT mode. Our results demonstrate that current high-resolution MSCT protocols could exceed the performance of a previous generation CBCT system for spatial resolution and image homogeneity. (orig.)

MSCT versus CBCT: evaluation of high-resolution acquisition modes for dento-maxillary and skull-base imaging

International Nuclear Information System (INIS)

Dillenseger, Jean-Philippe; Goetz, Christian; Matern, Jean-Francois; Gros, Catherine-Isabelle; Bornert, Fabien; Le Minor, Jean-Marie; Constantinesco, Andre; Choquet, Philippe

2015-01-01

Our aim was to conduct a quantitative and qualitative evaluation of high-resolution skull-bone imaging for dentistry and otolaryngology using different architectures of recent X-ray computed tomography systems. Three multi-slice computed tomography (MSCT) systems and one Cone-beam computed tomography (CBCT) system were used in this study. All apparatuses were tested with installed acquisition modes and proprietary reconstruction software enabling high-resolution bone imaging. Quantitative analyses were performed with small fields of view with the preclinical vmCT phantom, which permits to measure spatial resolution, geometrical accuracy, linearity and homogeneity. Ten operators performed visual qualitative analyses on the vmCT phantom images, and on dry human skull images. Quantitative analysis showed no significant differences between protocols in terms of linearity and geometric accuracy. All MSCT systems present a better homogeneity than the CBCT. Both quantitative and visual analyses demonstrate that CBCT acquisitions are not better than the collimated helical MSCT mode. Our results demonstrate that current high-resolution MSCT protocols could exceed the performance of a previous generation CBCT system for spatial resolution and image homogeneity. (orig.)

A multiresolution approach to iterative reconstruction algorithms in X-ray computed tomography.

Science.gov (United States)

De Witte, Yoni; Vlassenbroeck, Jelle; Van Hoorebeke, Luc

2010-09-01

In computed tomography, the application of iterative reconstruction methods in practical situations is impeded by their high computational demands. Especially in high resolution X-ray computed tomography, where reconstruction volumes contain a high number of volume elements (several giga voxels), this computational burden prevents their actual breakthrough. Besides the large amount of calculations, iterative algorithms require the entire volume to be kept in memory during reconstruction, which quickly becomes cumbersome for large data sets. To overcome this obstacle, we present a novel multiresolution reconstruction, which greatly reduces the required amount of memory without significantly affecting the reconstructed image quality. It is shown that, combined with an efficient implementation on a graphical processing unit, the multiresolution approach enables the application of iterative algorithms in the reconstruction of large volumes at an acceptable speed using only limited resources.

Computed Tomography evaluation of maxillofacial injuries

Directory of Open Access Journals (Sweden)

V Natraj Prasad

2017-01-01

Full Text Available Background & Objectives: The maxillofacial region, a complex anatomical structure, can be evaluated by conventional (plain films, Tomography, Multidetector Computed Tomography, Three-Dimensional Computed Tomography, Orthopantomogram and Magnetic Resonance Imaging. The study was conducted with objective of describing various forms of maxillofacial injuries, imaging features of different types of maxillofacial fractures and the advantage of using Three- Dimensional Computed Tomography reconstructed image. Materials & Methods: A hospital based cross-sectional study was conducted among 50 patients during April 2014 to September 2016 using Toshiba Aquilion Prime 160 slice Multi Detector Computed Tomography scanner.Results: The maxillofacial fractures were significantly higher in male population (88% than female population (12 %. Road traffic accidents were the most common cause of injury others being physical assault and fall from height. It was most common in 31-40 years (26% and 21-30 (24% years age group. Maxillary sinus was the commonest fracture (36% followed by nasal bone and zygomatic bone (30%, mandible and orbital bones (28%. Soft tissue swelling was the commonest associated finding. Three dimensional images (3 D compared to the axial scans missed some fractures. However, the extension of the complex fracture lines and degree of displacement were more accurately assessed. Complex fractures found were Le fort (6% and naso-orbito-ethmoid (4% fractures.Conclusion: The proper evaluation of complex anatomy of the facial bones requires Multidetector Computed Tomography which offers excellent spatial resolution enabling multiplanar reformations and three dimensional reconstructions for enhanced diagnostic accuracy and surgical planning.

Ultra-high resolution optical coherence tomography for encapsulation quality inspection

KAUST Repository

Czajkowski, Jakub

2011-08-28

We present the application of ultra-high resolution optical coherence tomography (UHR-OCT) in evaluation of thin, protective films used in printed electronics. Two types of sample were investigated: microscopy glass and organic field effect transistor (OFET) structure. Samples were coated with thin (1-3 μm) layer of parylene C polymer. Measurements were done using experimental UHR-OCT device based on a Kerr-lens mode locked Ti: sapphire femtosecond laser, photonic crystal fibre and modified, free-space Michelson interferometer. Submicron resolution offered by the UHR-OCT system applied in the study enables registration of both interfaces of the thin encapsulation layer. Complete, volumetric characterisation of protective layers is presented, demonstrating possibility to use OCT for encapsulation quality inspection. © Springer-Verlag 2011.

Transmission computed tomography data acquisition with a SPECT system

International Nuclear Information System (INIS)

Greer, K.L.; Harris, C.C.; Jaszczak, R.J.; Coleman, R.E.; Hedlund, L.W.; Floyd, C.E.; Manglos, S.H.

1987-01-01

Phantom and animal transmission computed tomography (TCT) scans were performed with a camera-based single photon emission computed tomography (SPECT) system to determine system linearity as a function of object density, which is important in the accurate determination of attenuation coefficients for SPECT attenuation compensation. Results from phantoms showed promise in providing a linear relationship in measuring density while maintaining good image resolution. Animal images were essentially free of artifacts. Transmission computed tomography scans derived from a SPECT system appear to have the potential to provide data suitable for incorporation in an attenuation compensation algorithm at relatively low (calculated) radiation doses to the subjects

Computational adaptive optics for broadband interferometric tomography of tissues and cells

Science.gov (United States)

Adie, Steven G.; Mulligan, Jeffrey A.

2016-03-01

Adaptive optics (AO) can shape aberrated optical wavefronts to physically restore the constructive interference needed for high-resolution imaging. With access to the complex optical field, however, many functions of optical hardware can be achieved computationally, including focusing and the compensation of optical aberrations to restore the constructive interference required for diffraction-limited imaging performance. Holography, which employs interferometric detection of the complex optical field, was developed based on this connection between hardware and computational image formation, although this link has only recently been exploited for 3D tomographic imaging in scattering biological tissues. This talk will present the underlying imaging science behind computational image formation with optical coherence tomography (OCT) -- a beam-scanned version of broadband digital holography. Analogous to hardware AO (HAO), we demonstrate computational adaptive optics (CAO) and optimization of the computed pupil correction in 'sensorless mode' (Zernike polynomial corrections with feedback from image metrics) or with the use of 'guide-stars' in the sample. We discuss the concept of an 'isotomic volume' as the volumetric extension of the 'isoplanatic patch' introduced in astronomical AO. Recent CAO results and ongoing work is highlighted to point to the potential biomedical impact of computed broadband interferometric tomography. We also discuss the advantages and disadvantages of HAO vs. CAO for the effective shaping of optical wavefronts, and highlight opportunities for hybrid approaches that synergistically combine the unique advantages of hardware and computational methods for rapid volumetric tomography with cellular resolution.

Geometrical analysis of woven fabric microstructure based on micron-resolution computed tomography data

Science.gov (United States)

Krieger, Helga; Seide, Gunnar; Gries, Thomas; Stapleton, Scott E.

2018-04-01

The global mechanical properties of textiles such as elasticity and strength, as well as transport properties such as permeability depend strongly on the microstructure of the textile. Textiles are heterogeneous structures with highly anisotropic material properties, including local fiber orientation and local fiber volume fraction. In this paper, an algorithm is presented to generate a virtual 3D-model of a woven fabric architecture with information about the local fiber orientation and the local fiber volume fraction. The geometric data of the woven fabric impregnated with resin was obtained by micron-resolution computed tomography (μCT). The volumetric μCT-scan was discretized into cells and the microstructure of each cell was analyzed and homogenized. Furthermore, the discretized data was used to calculate the local permeability tensors of each cell. An example application of the analyzed data is the simulation of the resin flow through a woven fabric based on the determined local permeability tensors and on Darcy's law. The presented algorithm is an automated and robust method of going from μCT-scans to structural or flow models.

Feasibility of Noninvasive Temperature Assessment During Radiofrequency Liver Ablation on Computed Tomography

NARCIS (Netherlands)

Pandeya, Ganga D.; Greuter, Marcel J. W.; de Jong, Koert P.; Schmidt, Bernhard; Flohr, Thomas; Oudkerk, Matthijs

2011-01-01

Purpose: The purpose of this study was to assess the feasibility of noninvasive thermometry using high-resolution computer tomography (CT) for the monitoring of bovine liver during radiofrequency (RF) ablation. Methods: Radiofrequency probes were used to ablate bovine livers from 20 degrees C to 98

Computed Tomography (CT) -- Sinuses

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Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses ... CT of the Sinuses? What is CT (Computed Tomography) of the Sinuses? Computed tomography, more commonly known ...

Use of Cone Beam Computed Tomography in Endodontics

Science.gov (United States)

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

2009-01-01

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

Development of a rapid multi-line detector for industrial computed tomography

International Nuclear Information System (INIS)

Nachtrab, Frank; Firsching, Markus; Hofmann, Thomas; Uhlmann, Norman; Neubauer, Harald; Nowak, Arne

2015-01-01

In this paper we present the development of a rapid multi-row detector is optimized for industrial computed tomography. With a high frame rate, high spatial resolution and the ability to use up to 450 kVp it is particularly suitable for applications such as fast acquisition of large objects, inline CT or time-resolved 4D CT. (Contains PowerPoint slides). [de

Conventional X-ray examination and computed tomography in inflammatory rheumatic diseases

International Nuclear Information System (INIS)

Lingg, G.

1996-01-01

Plain-film radiography is an important and basic element in the assessment of inflammatory rheumatic diseases. Its various uses include assessment of inflammatory osseous destruction and the activity of inflammatory changes. Furthermore, the inflammatory collateral phenomena can indicate an acute clinical phase, and the articular soft tissue swelling and tenosynovitis are shown directly and indirectly very clearly. On the other hand, high-resolution computed tomography is very capable of showing cortical structures of bone complementary to MR. In some special clinical questions and anatomical regions, especially the axial skeleton, it delivers information of high specifity, partly for definitive diagnosis and partly for planning surgical procedures. The assessment of changes in the sacroiliac joints, sternoclavicular joints and craniocervical junction are domains of computed tomography. (orig.) [de

Developmental approach towards high resolution optical coherence tomography for glaucoma diagnostics

Science.gov (United States)

Kemper, Björn; Ketelhut, Steffi; Heiduschka, Peter; Thorn, Marie; Larsen, Michael; Schnekenburger, Jürgen

2018-02-01

Glaucoma is caused by a pathological rise in the intraocular pressure, which results in a progressive loss of vision by a damage to retinal cells and the optical nerve head. Early detection of pressure-induced damage is thus essential for the reduction of eye pressure and to prevent severe incapacity or blindness. Within the new European Project GALAHAD (Glaucoma Advanced, Label free High Resolution Automated OCT Diagnostics), we will develop a new low-cost and high-resolution OCT system for the early detection of glaucoma. The device is designed to improve diagnosis based on a new system of optical coherence tomography. Although OCT systems are at present available in ophthalmology centres, high-resolution devices are extremely expensive. The novelty of the new Galahad system is its super wideband light source to achieve high image resolution at a reasonable cost. Proof of concept experiments with cell and tissue Glaucoma test standards and animal models are planned for the test of the new optical components and new algorithms performance for the identification of Glaucoma associated cell and tissue structures. The intense training of the software systems with various samples should result in a increased sensitivity and specificity of the OCT software system.

High energy near- and far-field ptychographic tomography at the ESRF

Science.gov (United States)

da Silva, Julio C.; Haubrich, Jan; Requena, Guillermo; Hubert, Maxime; Pacureanu, Alexandra; Bloch, Leonid; Yang, Yang; Cloetens, Peter

2017-09-01

In high-resolution tomography, one needs high-resolved projections in order to reconstruct a high-quality 3D map of a sample. X-ray ptychography is a robust technique which can provide such high-resolution 2D projections taking advantage of coherent X-rays. This technique was used in the far-field regime for a fair amount of time, but it can now also be implemented in the near-field regime. In both regimes, the technique enables not only high-resolution imaging, but also high sensitivity to the electron density of the sample. The combination with tomography makes 3D imaging possible via ptychographic X-ray computed tomography (PXCT), which can provide a 3D map of the complex-valued refractive index of the sample. The extension of PXCT to X-ray energies above 15 keV is challenging, but it can allow the imaging of object opaque to lower energy. We present here the implementation and developments of high-energy near- and far-field PXCT at the ESRF.

The neutron computer tomography

International Nuclear Information System (INIS)

Matsumoto, G.; Krata, S.

1983-01-01

The method of computer tomography (CT) was applied for neutrons instead of X-rays. The neutron radiography image of samples was scanned by microphotometer to get the transmission data. This process was so time-consuming that the number of incident angles to samples could not be increased. The transmission data was processed by FACOM computer and CT image was gained. In the experiment at the Japan Research Reactor No. 4 at Tokai-mura with 18 projection angles, the resolution of paraffin in the aluminum block was less than 0.8 mm. In the experiment at Van de Graaf accelerator of Nagoya University, this same resolution was 1.2 mm because of the angle distribution of neutron beam. This experiment is the preliminary one, the facility which utilizes neutron television and video-recorder will be necessary for the next stage. (Auth.)

The subclinical involvement of the lung in rheumatoid arthritis: evaluation by high-resolution computed tomography

Directory of Open Access Journals (Sweden)

E. Bichi Secchi

2011-09-01

Full Text Available Pulmonary involvement is one of the most frequent extra-articular manifestations of rheumatoid arthritis (RA and represents a serious complication, being the second cause of death after infection. High-resolution computed tomography (HRCT, owing to its increased sensitivity and diagnostic accuracy respect to the conventional chest radiograph (CXR, allows to detect pulmonary abnormalities in RA patients more frequently than CXR. The aim of this study was to assess pulmonary involvement by HRCT in lifelong non-smoking RA patients without symptoms and clinical signs of pulmonary disease. Seventy-two patients (54 women and 18 men with a mean age of 56.8±10.4 years (range, 40- 77 years and mean duration of disease of 6.9±4.7 years (range, 2-12 years entered the study. 52/72 (72% were positive for rheumatoid factor (> 20 UI/ml. Standard CXR and HRCT were carried out in each patient. CXR showed a mild interstitial fibrosis in 7 patients (9.7%, whereas HRCT demonstrated pulmonary abnormalities in an higher number of them (22/72 = 30.5%. The most frequent abnormal findings on HRCT were irregular pleural margins (13.8% and septal/subpleural lines (18%, both compatible with pulmonary fibrosis. Ground-glass opacities were found in 8.3% of the patients. Pulmonary nodules (diameter, range 0,5-2 cm predominantly located in the subpleural portions of the lung, were demonstrated in the same percentage (8.3% of patients. Small airway involvement, represented by bronchiectasis/bronchioloectasis, was shown in 15.2% of patients. Subpleural cysts were present in two cases (2.8%. No patient had evidence of honeycombing on HRCT. In conclusion, HRCT is an accurate, non-invasive and safe method of diagnosing lung abnormalities in RA patients without signs and clinical symptoms of pulmonary disease...

Computed tomography in low-back-pain after femur-amputation for osteogenic sarcoma

International Nuclear Information System (INIS)

Anda, S.; Moe, P.J.; Trondheim Univ.

1987-01-01

Following amputation of a lower extremity for osteogenic sarcoma, the lumbar muscles receive an asymmetric strain. This predisposes to low-back-pain. When this occurs, tumour-recurrence must be excluded. This report demonstrates the usefulness of high-resolution computer tomography (CT) in this clinical situation. (orig.)

Cone beam tomography of the heart using single-photon emission-computed tomography

International Nuclear Information System (INIS)

Gullberg, G.T.; Christian, P.E.; Zeng, G.L.; Datz, F.L.; Morgan, H.T.

1991-01-01

The authors evaluated cone beam single-photon emission-computed tomography (SPECT) of the heart. A new cone beam reconstruction algorithm was used to reconstruct data collected from short scan acquisitions (of slightly more than 180 degrees) of a detector anteriorally traversing a noncircular orbit. The less than 360 degrees acquisition was used to minimize the attenuation artifacts that result from reconstructing posterior projections of 201T1 emissions from the heart. The algorithm includes a new method for reconstructing truncated projections of background tissue activity that eliminates reconstruction ring artifacts. Phantom and patient results are presented which compare a high-resolution cone beam collimator (50-cm focal length; 6.0-mm full width at half maximum [FWHM] at 10 cm) to a low-energy general purpose (LEGP) parallel hole collimator (8.2-mm FWHM at 10 cm) which is 1.33 times more sensitive. The cone beam tomographic results are free of reconstruction artifacts and show improved spatial and contrast resolution over that obtained with the LEGP parallel hole collimator. The limited angular sampling restrictions and truncation problems associated with cone beam tomography do not deter from obtaining diagnostic information. However, even though these preliminary results are encouraging, a thorough clinical study is still needed to investigate the specificity and sensitivity of cone beam tomography

High-resolution computed tomography of the temporal bone. Part 2.: pathology

International Nuclear Information System (INIS)

Grzegorzewski, M.; Boron, Z.; Burzynska-Makuch, M.

1995-01-01

Selected cases of the temporal bone pathology on high resolution CT were demonstrated. Transverse and coronal sections of the cases were selected from 68 patients with various otological diseases. (author)

Spirometry-Assisted High Resolution Chest Computed Tomography in Children: Is it Worth the Effort?

Science.gov (United States)

Otjen, Jeffrey Parke; Swanson, Jonathan Ogden; Oron, Assaf; DiBlasi, Robert M; Swortzel, Tim; van Well, Jade Adriana Marie; Gommers, Eva Anna Elisabeth; Rosenfeld, Margaret

Image quality of high resolution chest computed tomographies (HRCTs) depends on adequate breath holds at end inspiration and end expiration. We hypothesized that implementation of spirometry-assisted breath holds in children undergoing HRCTs would improve image quality over that obtained with voluntary breath holds by decreasing motion artifact and atelectasis. This is a retrospective case-control study of HRCTs obtained at a tertiary care children's hospital before and after implementation of a spirometry-assisted CT protocol, in which children ≥8 years of age are first trained in supine slow vital capacity maneuvers and then repeat the maneuvers in the CT scanner, coached by a respiratory therapist. Spirometry-assisted CT scans (cases) were matched by age, gender and diagnosis (cystic fibrosis vs other) to CT scans obtained with voluntary breath holds in the 6 years before implementation of the spirometry assistance protocol (controls), and evaluated by 2 blinded pediatric radiologists. Among both cases and controls (N = 50 each), 10 carried the diagnosis of cystic fibrosis and 40 had other diagnoses. Mean age was 12.9 years (range: 7.5-20.1) among cases and 13.0 (7.1-19.7) among controls. Mean (SD) inspiratory image density among cases was -852 (37) Hounsfield units (HU) and -828 (43) among controls (p = 0.006). Mean (SD) expiratory image density was -629 (95) HU among cases and -688 (83) HU among controls (p = 0.002). Mean (SD) change in image density between inspiratory and expiratory images was +222 (85) HU among cases and +140 (76) HU among controls (p 0.80). Atelectasis was present on inspiratory images in 8 cases and 9 controls and on expiratory images in 9 cases and 10 controls (p > 0.80). Spirometry-assisted CTs had a significantly greater difference in lung density between inspiratory and expiratory scans than those performed with voluntary breath holds, likely improving the ability to detect air trapping. No appreciable difference in image quality

A simulation study of high-resolution x-ray computed tomography imaging using irregular sampling with a photon-counting detector

International Nuclear Information System (INIS)

Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

2013-01-01

The purpose of this study was to improve the spatial resolution for the x-ray computed tomography (CT) imaging with a photon-counting detector using an irregular sampling method. The geometric shift-model of detector was proposed to produce the irregular sampling pattern and increase the number of samplings in the radial direction. The conventional micro-x-ray CT system and the novel system with the geometric shift-model of detector were simulated using analytic and Monte Carlo simulations. The projections were reconstructed using filtered back-projection (FBP), algebraic reconstruction technique (ART), and total variation (TV) minimization algorithms, and the reconstructed images were compared in terms of normalized root-mean-square error (NRMSE), full-width at half-maximum (FWHM), and coefficient-of-variation (COV). The results showed that the image quality improved in the novel system with the geometric shift-model of detector, and the NRMSE, FWHM, and COV were lower for the images reconstructed using the TV minimization technique in the novel system with the geometric shift-model of detector. The irregular sampling method produced by the geometric shift-model of detector can improve the spatial resolution and reduce artifacts and noise for reconstructed images obtained from an x-ray CT system with a photon-counting detector. -- Highlights: • We proposed a novel sampling method based on a spiral pattern to improve the spatial resolution. • The novel sampling method increased the number of samplings in the radial direction. • The spatial resolution was improved by the novel sampling method

Comparison between conventional tomography and computer tomography in diseases of the sacroiliac joints

International Nuclear Information System (INIS)

Moritz, J.D.; Ganter, H.; Winter, C.; Evangelisches Krankenhaus, Giessen

1990-01-01

16 patients with diseases of the sacroiliac joints were examined both with computer tomography and with conventional tomography. Both techniques were characterized by a high sensitivity. Computer tomography was superior in exactly delineating the extent of the pathologic changes. In conventional tomography the joint surface was more blurred, erosions were larger, and signs of ankylosis were more expanded, so that the joints seemed to be more altered in 8 cases than demonstrated by computer tomography. Very accurate changes like subchondral cysts were recognized only in the computer tomograms. In all cases in which anteroposterior radiographs revealed no clear result, the authors recommend to additionally employ computer tomography. (orig.) [de

Use of Cone Beam Computed Tomography in Endodontics

Directory of Open Access Journals (Sweden)

William C. Scarfe

2009-01-01

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

Computed tomography imaging for superior semicircular canal dehiscence syndrome

International Nuclear Information System (INIS)

Dobeli, Karen

2006-01-01

Superior semicircular canal dehiscence is a newly described syndrome of sound and/or pressure induced vertigo. Computed tomography (CT) imaging plays an important role in confirmation of a defect in the bone overlying the canal. A high resolution CT technique utilising 0.5 mm or thinner slices and multi-planar reconstructions parallel to the superior semicircular canal is required. Placement of a histogram over a suspected defect can assist CT diagnosis

Computed tomography of the pancreas

International Nuclear Information System (INIS)

Kolmannskog, F.; Kolbenstvedt, A.; Aakhus, T.; Bergan, A.; Fausa, O.; Elgjo, K.

1980-01-01

The findings by computed tomography in 203 cases of suspected pancreatic tumours, pancreatitis or peripancreatic abnormalities were evaluated. The appearances of the normal and the diseased pancreas are described. Computed tomography is highly accurate in detecting pancreatic masses, but can not differentiate neoplastic from inflammatory disease. The only reliable signs of pancreatic carcinoma are a focal mass in the pancreas, together with liver metastasis. When a pancreatic mass is revealed by computed tomography, CT-guided fine-needle aspiration biopsy of the pancreas is recommended. Thus the need for more invasive diagnostic procedures and explorative laparotomy may be avoided in some patients. (Auth.)

Patient dose management practice in computed tomography with special emphasis to pediatric patients

International Nuclear Information System (INIS)

Kharita, M. H.; Wali, Kh.

2010-12-01

As per UNSCEAR 2000, CT contributes over 34% of collective dose from diagnostic X-Ray examinations in the world. The radiation dose in CT particular importance for children, it is very well known that children are more sensitive and likely to get radiation induced cancer than adults. This paper discusses the radiation dose of patients (adults and children) in Computed Tomography in syria ( 30 CT units form 6 different manufacturers). The radiation dose measurements has covered computed tomography dose index, dose length product and effective dose. The result of this study indicating, that most computed tomography dose index and dose length product values recorded were below dose reference levels, only for high resolution chest protocol, the dose length product results were higher than that of the International Commission on Radiological Protection (author)

Pattern of interstitial lung disease detected by high resolution ...

African Journals Online (AJOL)

Background: Diffuse lung diseases constitute a major cause of morbidity and mortality worldwide. High Resolution Computed Tomography (HRCT) is the recommended imaging technique in the diagnosis, assessment and followup of these diseases. Objectives: To describe the pattern of HRCT findings in patients with ...

Flat panel computed tomography of human ex vivo heart and bone specimens: initial experience

Energy Technology Data Exchange (ETDEWEB)

Nikolaou, Konstantin; Becker, Christoph R.; Reiser, Maximilian F. [Ludwig-Maximilians-University, Department of Clinical Radiology, Munich (Germany); Flohr, Thomas; Stierstorfer, Karl [CT Division, Siemens Medical Solutions, Forchheim (Germany)

2005-02-01

The aim of this technical investigation was the detailed description of a prototype flat panel detector computed tomography system (FPCT) and its initial evaluation in an ex vivo setting. The prototype FPCT scanner consists of a conventional radiographic flat panel detector, mounted on a multi-slice CT scanner gantry. Explanted human ex vivo heart and foot specimens were examined. Images were reformatted with various reconstruction algorithms and were evaluated for high-resolution anatomic information. For comparison purposes, the ex vivo specimens were also scanned with a conventional 16-detector-row CT scanner (Sensation 16, Siemens Medical Solutions, Forchheim, Germany). With the FPCT prototype used, a 1,024 x 768 resolution matrix can be obtained, resulting in an isotropic voxel size of 0.25 x 0.25 x 0.25 mm at the iso-center. Due to the high spatial resolution, very small structures such as trabecular bone or third-degree, distal branches of coronary arteries could be visualized. This first evaluation showed that flat panel detector systems can be used in a cone-beam computed tomography scanner and that very high spatial resolutions can be achieved. However, there are limitations for in vivo use due to constraints in low contrast resolution and slow scan speed. (orig.)

Prognostic Significance of Tumor Size of Small Lung Adenocarcinomas Evaluated with Mediastinal Window Settings on Computed Tomography

OpenAIRE

Sakao, Yukinori; Kuroda, Hiroaki; Mun, Mingyon; Uehara, Hirofumi; Motoi, Noriko; Ishikawa, Yuichi; Nakagawa, Ken; Okumura, Sakae

2014-01-01

BACKGROUND: We aimed to clarify that the size of the lung adenocarcinoma evaluated using mediastinal window on computed tomography is an important and useful modality for predicting invasiveness, lymph node metastasis and prognosis in small adenocarcinoma. METHODS: We evaluated 176 patients with small lung adenocarcinomas (diameter, 1-3 cm) who underwent standard surgical resection. Tumours were examined using computed tomography with thin section conditions (1.25 mm thick on high-resolution ...

Emission computed tomography

International Nuclear Information System (INIS)

Ott, R.J.

1986-01-01

Emission Computed Tomography is a technique used for producing single or multiple cross-sectional images of the distribution of radionuclide labelled agents in vivo. The techniques of Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are described with particular regard to the function of the detectors used to produce images and the computer techniques used to build up images. (UK)

An investigation of the potential of optical computed tomography for imaging of synchrotron-generated x-rays at high spatial resolution

International Nuclear Information System (INIS)

Doran, Simon J; Brochard, Thierry; Braeuer-Krisch, Elke; Adamovics, John; Krstajic, Nikola

2010-01-01

X-ray microbeam radiation therapy (MRT) is a novel form of treatment, currently in its preclinical stage, which uses microplanar x-ray beams from a synchrotron radiation source. It is important to perform accurate dosimetry on these microbeams, but, to date, there has been no accurate enough method available for making 3D dose measurements with isotropic, high spatial resolution to verify the results of Monte Carlo dose simulations. Here, we investigate the potential of optical computed tomography for satisfying these requirements. The construction of a simple optical CT microscopy (optical projection tomography) system from standard commercially available hardware is described. The measurement of optical densities in projection data is shown to be highly linear (r 2 = 0.999). The depth-of-field (DOF) of the imaging system is calculated based on the previous literature and measured experimentally using a commercial DOF target. It is shown that high quality images can be acquired despite the evident lack of telecentricity and despite DOF of the system being much lower than the sample diameter. Possible reasons for this are discussed. Results are presented for a complex irradiation of a 22 mm diameter cylinder of the radiochromic polymer PRESAGE(TM), demonstrating the exquisite 'dose-painting' abilities available in the MRT hutch of beamline ID-17 at the European Synchrotron Radiation Facility. Dose distributions in this initial experiment are equally well resolved on both an optical CT scan and a corresponding transmission image of radiochromic film, down to a line width of 83 μm (6 lp mm -1 ) with an MTF value of 0.40. A group of 33 μm wide lines was poorly resolved on both the optical CT and film images, and this is attributed to an incorrect exposure time calculation, leading to under-delivery of dose. Image artefacts in the optical CT scan are discussed. PRESAGE(TM) irradiated using the microbeam facility is proposed as a suitable material for producing

Ultra high resolution tomography

Energy Technology Data Exchange (ETDEWEB)

Haddad, W.S.

1994-11-15

Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography

Directory of Open Access Journals (Sweden)

Kopke Susan

2012-09-01

Full Text Available Abstract Background Recent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical computed tomography. More precise results were expected by using micro-computed tomography with a resolution of about 0.1 mm and three-dimensional reconstructions based on previous greyscale analyses and histological verification. The aim of the present study was to describe the physiological configurations of the pulp system within a wide spectrum of tooth ages. Results Maxillary teeth: All morphological constituents of the endodontic cavity were present in teeth between 4 and 16 years: Triadan 06s displayed six pulp horns and five root canals, Triadan 07-10s five pulp horns and four root canals and Triadan 11s seven pulp horns and four to six root canals. A common pulp chamber was most frequent in teeth ≤5 years, but was found even in a tooth of 9 years. A large variety of pulp configurations was observed within 2.5 and 16 years post eruption, but most commonly a separation into mesial and distal pulp compartments was seen. Maxillary cheek teeth showed up to four separate pulp compartments but the frequency of two, three and four pulp compartments was not related to tooth age (P > 0.05. In Triadan 06s, pulp horn 6 was always connected to pulp horns 1 and 3 and root canal I. In Triadan 11s, pulp horns 7 and 8 were present in variable constitutions. Mandibular teeth: A common pulp chamber was present in teeth up to 15 years, but most

Computer simulation of high resolution transmission electron micrographs: theory and analysis

International Nuclear Information System (INIS)

Kilaas, R.

1985-03-01

Computer simulation of electron micrographs is an invaluable aid in their proper interpretation and in defining optimum conditions for obtaining images experimentally. Since modern instruments are capable of atomic resolution, simulation techniques employing high precision are required. This thesis makes contributions to four specific areas of this field. First, the validity of a new method for simulating high resolution electron microscope images has been critically examined. Second, three different methods for computing scattering amplitudes in High Resolution Transmission Electron Microscopy (HRTEM) have been investigated as to their ability to include upper Laue layer (ULL) interaction. Third, a new method for computing scattering amplitudes in high resolution transmission electron microscopy has been examined. Fourth, the effect of a surface layer of amorphous silicon dioxide on images of crystalline silicon has been investigated for a range of crystal thicknesses varying from zero to 2 1/2 times that of the surface layer

Computed tomography in the evaluation of acquired stenosis in the neonate

International Nuclear Information System (INIS)

Faw, K.; Muntz, H.; Siegel, M.; Spector, G.

1982-01-01

We studied the feasibility of computed tomographic evaluation of the neonatal airway. Three neonatal larynges, removed at necroscopy, were examined by computed tomography. Good resolution of soft tissue, cartilage and airway lumen was obtained in these small specimens. On the basis of these findings two neonates with acquired subglottic stenosis were examined by endoscopy, soft tissue airway radiographs, and computed tomography. Measurements of radiation dose revealed that a computed tomographic study delivered 36% of the mean tissue dose of standard image intensifier fluoroscopy. Computed tomography and fluoroscopy both demonstrated the degree and length of this stenosis accurately. An advantage of CT over conventional imaging procedures was better definition of the cross sectional area of the airway

Signal Amplification Technique (SAT): an approach for improving resolution and reducing image noise in computed tomography

International Nuclear Information System (INIS)

Phelps, M.E.; Huang, S.C.; Hoffman, E.J.; Plummer, D.; Carson, R.

1981-01-01

Spatial resolution improvements in computed tomography (CT) have been limited by the large and unique error propagation properties of this technique. The desire to provide maximum image resolution has resulted in the use of reconstruction filter functions designed to produce tomographic images with resolution as close as possible to the intrinsic detector resolution. Thus, many CT systems produce images with excessive noise with the system resolution determined by the detector resolution rather than the reconstruction algorithm. CT is a rigorous mathematical technique which applies an increasing amplification to increasing spatial frequencies in the measured data. This mathematical approach to spatial frequency amplification cannot distinguish between signal and noise and therefore both are amplified equally. We report here a method in which tomographic resolution is improved by using very small detectors to selectively amplify the signal and not noise. Thus, this approach is referred to as the signal amplification technique (SAT). SAT can provide dramatic improvements in image resolution without increases in statistical noise or dose because increases in the cutoff frequency of the reconstruction algorithm are not required to improve image resolution. Alternatively, in cases where image counts are low, such as in rapid dynamic or receptor studies, statistical noise can be reduced by lowering the cutoff frequency while still maintaining the best possible image resolution. A possible system design for a positron CT system with SAT is described

Solitary pulmonary metastases in high-risk melanoma patients: a prospective comparison of conventional and computed tomography

International Nuclear Information System (INIS)

Heaston, D.K.; Putman, C.E.; Rodan, B.A.; Nicholson, E.; Ravin, C.E.; Korobkin, M.; Chen, J.T.; Seigler, H.F.

1983-01-01

A prospective comparison of chest radiography, conventional tomography, and computed tomography (CT) in the detection or confirmation of solitary pulmonary nodules was made in 42 patients with high propensity for pulmonary metastases due to advanced local (Clark level IV or V) or regional malignant melanoma. Unequivocal nodules were revealed by chest radiography in 11 patients, conventional tomograhy in 16, and computed tomography in 20 patients. Both plain films and tomography in three of these 20 were normal, but follow-up verified pulmonary metastases. Computed tomography detected more pulmonary nodules than conventional tomography in 11 patients in addition to identifying lesions in extrapulmonary sites. Therefore, chest CT is recommended before institution of immunotherapy or surgical removal of a solitary pulmonary melanoma metastasis. Once chemotherapy had been instituted for bulky regional or cutaneous involvement, however, the findings of either conventional or computed tomography were comparable in this study

High-resolution computed tomography to differentiate chronic diffuse interstitial lung diseases with predominant ground-glass pattern using logical analysis of data

International Nuclear Information System (INIS)

Martin, Sophie Grivaud; Brauner, Michel W.; Rety, Frederique; Kronek, Louis-Philippe; Brauner, Nadia; Valeyre, Dominique; Nunes, Hilario; Brillet, Pierre-Yves

2010-01-01

We evaluated the performance of high-resolution computed tomography (HRCT) to differentiate chronic diffuse interstitial lung diseases (CDILD) with predominant ground-glass pattern by using logical analysis of data (LAD). A total of 162 patients were classified into seven categories: sarcoidosis (n = 38), connective tissue disease (n = 32), hypersensitivity pneumonitis (n = 18), drug-induced lung disease (n = 15), alveolar proteinosis (n = 12), idiopathic non-specific interstitial pneumonia (n = 10) and miscellaneous (n = 37). First, 40 CT attributes were investigated by the LAD to build up patterns characterising a category. From the association of patterns, LAD determined models specific to each CDILD. Second, data were recomputed by adding eight clinical attributes to the analysis. The 20 x 5 cross-folding method was used for validation. Models could be individualised for sarcoidosis, hypersensitivity pneumonitis, connective tissue disease and alveolar proteinosis. An additional model was individualised for drug-induced lung disease by adding clinical data. No model was demonstrated for idiopathic non-specific interstitial pneumonia and the miscellaneous category. The results showed that HRCT had a good sensitivity (≥64%) and specificity (≥78%) and a high negative predictive value (≥93%) for diseases with a model. Higher sensitivity (≥78%) and specificity (≥89%) were achieved by adding clinical data. The diagnostic performance of HRCT is high and can be increased by adding clinical data. (orig.)

Performance of cone-beam computed tomography and multidetector computed tomography in diagnostic imaging of the midface: A comparative study on Phantom and cadaver head scans

Energy Technology Data Exchange (ETDEWEB)

Veldhoen, Simon [University Medical Center Hamburg, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); University Hospital Wuerzburg, Department of Diagnostic and Interventional Radiology, Wuerzburg (Germany); Schoellchen, Maximilian; Hanken, H.; Precht, C.; Heiland, M. [University Medical Center Hamburg, Department of Oral- and Maxillofacial Surgery, Hamburg (Germany); Henes, F.O.; Adam, G.; Regier, M. [University Medical Center Hamburg, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Schoen, G. [University Medical Center Hamburg, Department of Medical Biometry and Epidemiology, Hamburg (Germany); Nagel, H.D. [Science and Technology for Radiology, Buchholz (Germany); Schumacher, U. [University Medical Center Hamburg, Institute of Anatomy, Hamburg (Germany)

2017-02-15

To compare multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) regarding radiation, resolution, image noise, and image quality. CBCT and 256-MDCT were compared based on three scan protocols: Standard-dose (∼24 mGy), reduced-dose (∼9 mGy), and low-dose (∼4 mGy). MDCT images were acquired in standard- and high-resolution mode (HR-MDCT) and reconstructed using filtered back projection (FBP) and iterative reconstruction (IR). Spatial resolution in linepairs (lp) and objective image noise (OIN) were assessed using dedicated phantoms. Image quality was assessed in scans of 25 cadaver heads using a Likert scale. OIN was markedly higher in FBP-MDCT when compared to CBCT. IR lowered the OIN to comparable values in standard-mode MDCT only. CBCT provided a resolution of 13 lp/cm at standard-dose and 11 lp/cm at reduced-dose vs. 11 lp/cm and 10 lp/cm in HR-MDCT. Resolution of 10 lp/cm was observed for both devices using low-dose settings. Quality scores of MDCT and CBCT did not differ at standard-dose (CBCT, 3.4; MDCT, 3.3-3.5; p > 0.05). Using reduced- and low-dose protocols, CBCT was superior (reduced-dose, 3.2 vs. 2.8; low dose, 3.0 vs. 2.3; p < 0.001). Using the low-dose protocol, the assessed CBCT provided better objective and subjective image quality and equality in resolution. Similar image quality, but better resolution using CBCT was observed at higher exposure settings. (orig.)

Computed tomography characteristics suggestive of spontaneous resolution of chronic subdural hematoma

Energy Technology Data Exchange (ETDEWEB)

Horikoshi, Toru; Naganuma, Hirofumi; Fukasawa, Isao; Uchida, Mikito; Nukui, Hideaki [Yamanashi Medical Univ., Tamaho (Japan)

1998-09-01

The clinical and radiological characteristics of self-resolving hematoma were assessed retrospectively in a series of patients with chronic subdural hematomas (SDHs) treated over a recent 6-year period in a local hospital. Spontaneous resolution was observed in five of 27 hematomas occurring in four of 23 patients. Clinical and radiological findings of the four cases were compared to those of the remaining 19 cases. All spontaneously resolving SDHs were asymptomatic or only caused mild transient headache, and disappeared within 4 to 9 months after head injury. All spontaneously resolving SDHs were located in the frontal region, and maximum thickness and midline displacement were less than those in the other 19 patients who were symptomatic and underwent surgery. Computed tomography demonstrated a low density line between the hematoma and the cerebral cortex, indicative of remaining cerebrospinal fluid space in four of five hematomas. Spontaneously resolving SDH is more frequent than formerly expected. Asymptomatic SDHs localized in the frontal region with small mass signs can be expected to disappear spontaneously without deterioration. (author)

Computed Tomography (CT) -- Head

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

Visualization of flaws within heavy section ultrasonic test blocks using high energy computed tomography

International Nuclear Information System (INIS)

House, M.B.; Ross, D.M.; Janucik, F.X.; Friedman, W.D.; Yancey, R.N.

1996-05-01

The feasibility of high energy computed tomography (9 MeV) to detect volumetric and planar discontinuities in large pressure vessel mock-up blocks was studied. The data supplied by the manufacturer of the test blocks on the intended flaw geometry were compared to manual, contact ultrasonic test and computed tomography test data. Subsequently, a visualization program was used to construct fully three-dimensional morphological information enabling interactive data analysis on the detected flaws. Density isosurfaces show the relative shape and location of the volumetric defects within the mock-up blocks. Such a technique may be used to qualify personnel or newly developed ultrasonic test methods without the associated high cost of destructive evaluation. Data is presented showing the capability of the volumetric data analysis program to overlay the computed tomography and destructive evaluation (serial metallography) data for a direct, three-dimensional comparison

Wegener's granulomatosis: chest computed tomography findings; Granulomatose de Wegener: aspectos na tomografia computadorizada de torax

Energy Technology Data Exchange (ETDEWEB)

Monteiro, Evelise de Azevedo; Marchiori, Edson; Martins, Erick Malheiro Leoncio [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia]. E-mail: edmarchiori@zipmail.com.br; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Hospital de Base; Cerqueira, Elza Maria F.P. de [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Radiologia; Irion, Klaus L. [Pavilhao Pereira Filho, Porto Alegre, RS (Brazil); Araujo Neto, Cesar de [Bahia Univ., Salvador, BA (Brazil). Dept. de Radiologia; Souza, Rodrigo Azeredo de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia

2003-03-01

Wegeners granulomatosis is an inflammatory systemic necrotizing idiopathic vasculitis affecting mainly small vessels. In this paper we analyzed the computed tomography findings of seven patients with Wegeners granulomatosis. The most common findings were masses and nodules (71.4%), areas of ground glass attenuation (57.1%), consolidation (42.8%), halo sign (42.8%), cavitation (42.8%), interlobular septa thickening (14.2%), bronchial wall thickening (14.2%) and pleural effusion (14.2%). Although radiological findings are mostly nonspecific, computed tomography and particularly high-resolution computed tomography are important tools in the evaluation of disease activity when evaluated in association with bronchoscopy findings and clinical data. (author)

Speeding up image reconstruction in computed tomography

CERN Multimedia

CERN. Geneva

2018-01-01

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

High-resolution computed tomography of the chest in children with cystic fibrosis: support for use as an outcome surrogate

Energy Technology Data Exchange (ETDEWEB)

Brody, A.S. [Departments of Radiology and Pediatrics, Children`s Hospital Medical Center, Cincinnati, OH (United States)]|[University of Cincinnati School of Medicine, Children`s Hospital Medical Center, Cincinnati, OH (United States)]|[Department of Radiology, Cincinnati, OH (United States); Molina, P.L. [Department of Radiology, University of North Carolina at Chapel Hill, North Carolina (United States); Klein, J.S. [Department of Radiology, University of Vermont, Burlington, Vermont (United States); Rothman, B.S. [University of Cincinnati School of Medicine, Children`s Hospital Medical Center, Cincinnati, OH (United States); Ramagopal, M.; Swartz, D.R. [Department of Pediatrics, University of Vermont, Burlington, Vermont (United States)

1999-10-01

Background. Outcome surrogates are indicators that reflect, rather than directly measure, patient benefit. In order to provide useful results, however, outcome surrogates must be carefully chosen and must meet specific criteria. Objective. To support development of high-resolution computed tomography (HRCT) as an outcome surrogate in cystic fibrosis (CF) by demonstrating the ability of HRCT to show short-term improvement in the appearance of the lungs in children with CF. Materials and methods. HRCT was performed at admission and after discharge on 8 children during 15 admissions for acute pulmonary exacerbation of CF. Three radiologists scored each study separately, then compared admission and discharge pairs. Results. HRCT scores improved in 13/15 admissions. Mean score decreased from 25 to 22. The decrease was significant (P = 0.014). Comparison of admission and discharge scans showed improvement in peribronchial thickening (P = 0.007), mucous plugging (P = 0.002), and overall appearance (P = 0.025). Conclusion. HRCT has the potential to be a useful outcome surrogate in CF. A necessary attribute of an outcome surrogate is that it improves rapidly with effective therapy. Despite widespread belief among radiologists and pulmonologists that HRCT meets this criterion, no previous report has demonstrated this ability in children. These findings support further development of HRCT as an outcome surrogate in children with CF. (orig.) With 2 figs., 2 tabs., 18 refs.

Changes in structural lung disease in cystic fibrosis children over 4 years as evaluated by high-resolution computed tomography

Energy Technology Data Exchange (ETDEWEB)

Carpio, Carlos; Alvarez-Sala, Rodolfo; Prados, Concepcion [University Hospital La Paz, La Paz Hospital Research Institute, Department of Respiratory Medicine, Madrid (Spain); Albi, Gustavo [Nino de Jesus Children' s Hospital, Department of Radiology, Madrid (Spain); Rayon-Aledo, Jose Carlos; Caballero, Paloma [University Hospital La Princesa, Department of Radiology, Madrid (Spain); Giron, Rosa [University Hospital La Princesa, Department of Respiratory Medicine, Madrid (Spain)

2015-12-15

To compare the worsening of structural lung disease on high-resolution computed tomography (HRCT) with changes in spirometry results in cystic fibrosis (CF) patients, and analyse factors associated with the worsening of structural lung disease over time. A total of 31 CF subjects (mean age 11.03 ± 3.67 years old) were prospectively evaluated by two HRCT and spirometry tests performed 4 years apart. HRCT abnormalities were scored using the Bhalla scoring system. Comparisons between changes on HRCT and spirometry were made for all patients, and also for groups categorized by age, sex, genotypic alterations and lung obstruction. The mean HRCT Bhalla scoring, forced expiratory volume in 1 s (FEV{sub 1} %pred.) and forced vital capacity (FVC %pred.) were 7.92 ± 3.59, 87.76 ± 20.52 and 96.54 ± 15.12, respectively. There was a significant deterioration in the Bhalla score (p < 0.01) and in certain categories: severity of bronchiectasis, peribronchial thickening, mucous plugging and bronchial divisions. Females had a more pronounced worsening of the Bhalla score than males (p = 0.048). No change over time was found in FEV{sub 1} and FVC. Only sex was associated with a deterioration in HRCT. HRCT Bhalla scoring changes statistically significantly over 4 years, but spirometry results do not. Worsening on HRCT is more evident in females. (orig.)

Changes in structural lung disease in cystic fibrosis children over 4 years as evaluated by high-resolution computed tomography

International Nuclear Information System (INIS)

Carpio, Carlos; Alvarez-Sala, Rodolfo; Prados, Concepcion; Albi, Gustavo; Rayon-Aledo, Jose Carlos; Caballero, Paloma; Giron, Rosa

2015-01-01

To compare the worsening of structural lung disease on high-resolution computed tomography (HRCT) with changes in spirometry results in cystic fibrosis (CF) patients, and analyse factors associated with the worsening of structural lung disease over time. A total of 31 CF subjects (mean age 11.03 ± 3.67 years old) were prospectively evaluated by two HRCT and spirometry tests performed 4 years apart. HRCT abnormalities were scored using the Bhalla scoring system. Comparisons between changes on HRCT and spirometry were made for all patients, and also for groups categorized by age, sex, genotypic alterations and lung obstruction. The mean HRCT Bhalla scoring, forced expiratory volume in 1 s (FEV 1 %pred.) and forced vital capacity (FVC %pred.) were 7.92 ± 3.59, 87.76 ± 20.52 and 96.54 ± 15.12, respectively. There was a significant deterioration in the Bhalla score (p < 0.01) and in certain categories: severity of bronchiectasis, peribronchial thickening, mucous plugging and bronchial divisions. Females had a more pronounced worsening of the Bhalla score than males (p = 0.048). No change over time was found in FEV 1 and FVC. Only sex was associated with a deterioration in HRCT. HRCT Bhalla scoring changes statistically significantly over 4 years, but spirometry results do not. Worsening on HRCT is more evident in females. (orig.)

High-resolution computed tomography of the chest in children with cystic fibrosis: support for use as an outcome surrogate

International Nuclear Information System (INIS)

Brody, A.S.; Molina, P.L.; Klein, J.S.; Rothman, B.S.; Ramagopal, M.; Swartz, D.R.

1999-01-01

Background. Outcome surrogates are indicators that reflect, rather than directly measure, patient benefit. In order to provide useful results, however, outcome surrogates must be carefully chosen and must meet specific criteria. Objective. To support development of high-resolution computed tomography (HRCT) as an outcome surrogate in cystic fibrosis (CF) by demonstrating the ability of HRCT to show short-term improvement in the appearance of the lungs in children with CF. Materials and methods. HRCT was performed at admission and after discharge on 8 children during 15 admissions for acute pulmonary exacerbation of CF. Three radiologists scored each study separately, then compared admission and discharge pairs. Results. HRCT scores improved in 13/15 admissions. Mean score decreased from 25 to 22. The decrease was significant (P = 0.014). Comparison of admission and discharge scans showed improvement in peribronchial thickening (P = 0.007), mucous plugging (P = 0.002), and overall appearance (P = 0.025). Conclusion. HRCT has the potential to be a useful outcome surrogate in CF. A necessary attribute of an outcome surrogate is that it improves rapidly with effective therapy. Despite widespread belief among radiologists and pulmonologists that HRCT meets this criterion, no previous report has demonstrated this ability in children. These findings support further development of HRCT as an outcome surrogate in children with CF. (orig.)

Comparison of initial high resolution computed tomography features in viral pneumonia between metapneumovirus infection and severe acute respiratory syndrome

International Nuclear Information System (INIS)

Wong, Cheuk Kei Kathy; Lai, Vincent; Wong, Yiu Chung

2012-01-01

Objective: To review and compare initial high resolution computed tomography (HRCT) findings in patients with metapneumovirus pneumonia and severe acute respiratory syndrome (SARS-Coronovirus). Materials and methods: 4 cases of metapneumovirus pneumonia (mean age of 52.3 years) in an institutional outbreak (Castle Peak Hospital) in 2008 and 38 cases of SARS-coronovirus (mean age of 39.6 years) admitted to Tuen Mun hospital during an epidemic outbreak in 2003 were included. HRCT findings of the lungs for all patients were retrospectively reviewed by two independent radiologists. Results: In the metapneumovirus group, common HRCT features were ground glass opacities (100%), consolidation (100%), parenchymal band (100%), bronchiectasis (75%). Crazy paving pattern was absent. They were predominantly subpleural and basal in location and bilateral involvement was observed in 50% of patients. In the SARS group, common HRCT features were ground glass opacities (92.1%), interlobular septal thickening (86.8%), crazy paving pattern (73.7%) and consolidation (68%). Bronchiectasis was not seen. Majority of patient demonstrated segmental or lobar in distribution and bilateral involvement was observed in 44.7% of patients. Pleural effusion and lymphadenopathy were of consistent rare features in both groups. Conclusion: Ground glass opacities, interlobular septal thickening and consolidations were consistent HRCT manifestations in both metapneumovirus infection and SARS. The presence of bronchiectasis (0% in SARS) may point towards metapneumovirus while crazy paving pattern is more suggestive of SARS.

Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

International Nuclear Information System (INIS)

Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki

2000-01-01

We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

Analyses of the eustachian tube and its surrounding tissues with cross sectional images by high-resolution computed tomography (HR-CT)

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Haruo; Kobayashi, Toshimitsu; Takasaki, Kenji; Kanda, Yukihiko; Nakao, Yoshiaki; Morikawa, Minoru; Ishimaru, Hideki; Hayashi, Kuniaki [Nagasaki Univ. (Japan). School of Medicine

2000-07-01

We attempted to image the eustachian tube (ET) and its surrounding tissues by high-resolution computed tomography (HR-CT). Twenty-two normal subjects (44 ears) without middle ear problems were studied, and a patient with severe patulous ET was also studied as an abnormal case. In our device of multiplanar reconstruction technique, we were able to obtain the clear reconstructed images of the ET lumen as well as of its surrounding tissues (bone, ET cartilage, tensor veli palatini muscle, levator veli palatini muscle, Ostmann's fat tissue, tensor tympani muscle, internal carotid artery) at any desired portion, either parallel or perpendicular to the long axis of the ET. However, the exact borders between the ET cartilage and the muscles, Ostmann's fat tissue and the tubal gland were not clearly identified. In the severe case of patulous ET, the ET lumen was widely opened at each cross-sectional image from the pharyngeal orifice to the tympanic orifice, in contrast with its being closed at the cartilaginous portion in the normal cases. In addition, the fat tissue and glands around the ET lumen were not clearly identified in this case. We suggest that this method will lead to better understanding of the ET-related diseases such as patulous ET. (author)

High-resolution emission tomography of small laboratory animals: physics and gamma-astronomy meet molecular biology

International Nuclear Information System (INIS)

Beekman, F.J.; Colijn, A.P.; Vastenhouw, B.; Wiegant, V.M.; Gerrits, M.A.F.M.

2003-01-01

Molecular imaging can be defined as the characterization and measurement of biological processes in living animals, model systems and humans at the cellular and molecular level using remote imaging detectors. An example concerns the mapping of the distributions of radioactively labeled molecules in laboratory animals which is of crucial importance for life sciences. Tomographic methods like Single Photon Emission Computed Tomography (SPECT) offer a possibility to visualize distributions of radioactively labeled molecules in living animals. Miniature tomography systems, derived from their clinical counterparts, but with a much higher image resolution are under development in several institutes. An example is U-SPECT that will be discussed in the present paper. Such systems are expected to accelerate several biomedical research procedures, the understanding of gene and protein function, as well as pharmaceutical development

Computed Tomography (CT) -- Sinuses

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Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Sinuses Computed tomography (CT) of the sinuses uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

Computed Tomography (CT) -- Head

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Full Text Available ... Physician Resources Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special x-ray equipment ... story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content ...

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

Science.gov (United States)

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

2015-01-01

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

Study on a high resolution positron emission tomography scanner for brain study

International Nuclear Information System (INIS)

Nohara, N.; Tomitani, T.; Yamamoto, M.; Murayama, H.; Tanaka, E.

1990-01-01

The spatial resolution of positron emission tomography (PET) scanners is usually limited by the finite size of crystals such as bismuth germanate (BGO). To attain high resolution as well as high sensitivity, it is essential to use a large number of small BGO crystals arranged in close-packing on circular rings. In developing high resolution PET scanners, however, there are two physical factors limiting the spatial resolution. One is the finite range of positrons before annihilation and the other the deviation from 180 degrees of annihilation photons. The effect of the factors on the spatial resolution has been evaluated for positron-emitting sources as a function of detector ring radius. A high resolution PET scanner has been developed for brain study, aiming to have spatial resolutions as high as less than 4-mm FWHM in tomographic plane and less than 6-mm FWHM in axial direction at the detector ring center. For the goal of the high resolutions a multi-segment type of photomultiplier tubes has been specially designed and developed, which allows one tube to be directly coupled by four BGO crystals. The scanner consists of five detector rings of 47-cm in diameter, using all 1200 BGO crystals each measuring 5 mm x 12 mm x 30 mm. The scanner provides simultaneous 9 images by combination of in-plane and cross-plane, offering a 24-cm dia. x7.4-cm field-of-view. Physical performance of the scanner was investigated. At the ring center, the spatial resolution in the tomographic plane was measured to be 3.5-mm FWHM. The axial resolution was measured to be 5.7-mm FWHM for in-plane and 5.3-mm FWHM for cross-plane. Sensitivity for a 20-cm dia. uniform source was measured to be 9.5 kcps/μCi/ml for in-plane and 15.3 kcps/μCi/ml for cross-plane. (J.P.N.)

A true minimally invasive approach for cochlear implantation: high accuracy in cranial base navigation through flat-panel-based volume computed tomography.

Science.gov (United States)

Majdani, Omid; Bartling, Soenke H; Leinung, Martin; Stöver, Timo; Lenarz, Minoo; Dullin, Christian; Lenarz, Thomas

2008-02-01

High-precision intraoperative navigation using high-resolution flat-panel volume computed tomography makes feasible the possibility of minimally invasive cochlear implant surgery, including cochleostomy. Conventional cochlear implant surgery is typically performed via mastoidectomy with facial recess to identify and avoid damage to vital anatomic landmarks. To accomplish this procedure via a minimally invasive approach--without performing mastoidectomy--in a precise fashion, image-guided technology is necessary. With such an approach, surgical time and expertise may be reduced, and hearing preservation may be improved. Flat-panel volume computed tomography was used to scan 4 human temporal bones. A drilling channel was planned preoperatively from the mastoid surface to the round window niche, providing a margin of safety to all functional important structures (e.g., facial nerve, chorda tympani, incus). Postoperatively, computed tomographic imaging and conventional surgical exploration of the drilled route to the cochlea were performed. All 4 specimens showed a cochleostomy located at the scala tympani anterior inferior to the round window. The chorda tympani was damaged in 1 specimen--this was preoperatively planned as a narrow facial recess was encountered. Using flat-panel volume computed tomography for image-guided surgical navigation, we were able to perform minimally invasive cochlear implant surgery defined as a narrow, single-channel mastoidotomy with cochleostomy. Although this finding is preliminary, it is technologically achievable.

Multi-resolution voxel phantom modeling: a high-resolution eye model for computational dosimetry.

Science.gov (United States)

Caracappa, Peter F; Rhodes, Ashley; Fiedler, Derek

2014-09-21

Voxel models of the human body are commonly used for simulating radiation dose with a Monte Carlo radiation transport code. Due to memory limitations, the voxel resolution of these computational phantoms is typically too large to accurately represent the dimensions of small features such as the eye. Recently reduced recommended dose limits to the lens of the eye, which is a radiosensitive tissue with a significant concern for cataract formation, has lent increased importance to understanding the dose to this tissue. A high-resolution eye model is constructed using physiological data for the dimensions of radiosensitive tissues, and combined with an existing set of whole-body models to form a multi-resolution voxel phantom, which is used with the MCNPX code to calculate radiation dose from various exposure types. This phantom provides an accurate representation of the radiation transport through the structures of the eye. Two alternate methods of including a high-resolution eye model within an existing whole-body model are developed. The accuracy and performance of each method is compared against existing computational phantoms.

Increased fluoro-deoxy-D-glucose uptake on positron emission tomography-computed tomography postbronchoalveolar lavage: a potential cause of radiologic misinterpretation.

LENUS (Irish Health Repository)

Leong, Sum

2011-08-01

Cytologic analysis of bronchoalveolar lavage (BAL) fluid is used for lung cancer diagnosis. We describe a patient with a history of rectal carcinoma who presented with a new lung mass. BAL was performed, with positron emission tomography-computed tomography the following day. There was mildly increased fluoro-deoxy-D-glucose uptake in areas of the lung parenchyma with new ground-glass opacification. This created ambiguity in staging, clarified 2 weeks later by a computed tomography showing complete resolution of the ground-glass opacity. Clinicians should be aware that BAL may cause increased pulmonary fluoro-deoxy-D-glucose uptake, making accurate radiologic interpretation problematic. We suggest that to optimize positron emission tomography-computed tomography, studies should not be performed within 24 hours of BAL.

Paradoxical emboli: demonstration using helical computed tomography of the pulmonary artery associated with abdominal computed tomography

International Nuclear Information System (INIS)

Delalu, P.; Ferretti, G.R.; Bricault, I.; Ayanian, D.; Coulomb, M.

2000-01-01

We report the case of a 60-year-old woman with a recent history of a cerebrovascular accident. Because of clinical suspicion of pulmonary embolism and negative Doppler ultrasound findings of the lower limbs, spiral computed tomography of the pulmonary artery was performed and demonstrated pulmonary emboli. We emphasize the role of computed tomography of the abdomen, performed 3 min after the thoracic acquisition, which showed an unsuspected thrombus within the abdominal aorta and the left renal artery with infarction of the left kidney. Paradoxical embolism was highly suspected on computed tomography data and confirmed by echocardiography which demonstrated a patent foramen ovale. (orig.)

High resolution functional photoacoustic tomography of breast cancer

Energy Technology Data Exchange (ETDEWEB)

Li, Xiaoqi; Yao, Lei; Xi, Lei; Jiang, Huabei, E-mail: hjiang@bme.ufl.edu [Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Heldermon, Coy D. [Department of Medicine, University of Florida, Gainesville, Florida 32611 (United States)

2015-09-15

Purpose: To evaluate the feasibility of functional photoacoustic tomography (fPAT) for high resolution detection and characterization of breast cancer and to demonstrate for the first time quantitative hemoglobin concentration and oxygen saturation images of breasts that were formed with model-based reconstruction of tomographic photoacoustic data. Methods: The study was HIPAA compliant and was approved by the university institutional review board. Written informed consents were obtained from all the participants. Ten cases, including six cancer and four healthy (mean age = 50 yr; age range = 41–66 yr), were examined. Functional images of breast tissue including absolute total hemoglobin concentration (Hb{sub T}) and oxygen saturation (StO{sub 2}%) were obtained by fPAT and cross validated with magnetic resonance imaging (MRI) readings and/or histopathology. Results: Hb{sub T} and StO{sub 2}% maps from all six pathology-confirmed cancer cases (60%) show clear detection of tumor, while MR images indicate clear detection of tumor for five of six cancer cases; one small tumor was read as near-complete-resolution by MRI. The average Hb{sub T} and StO{sub 2}% value of suspicious lesion area for the cancer cases was 61.6 ± 18.9 μM/l and 67.5% ± 5.2% compared to 25.6 ± 7.4 μM/l and 65.2% ± 3.8% for background normal tissue. Conclusions: fPAT has the potential to be a significant add-on in breast cancer detection and characterization as it provides submillimeter resolution functional images of breast lesions.

High-resolution computer-aided moire

Science.gov (United States)

Sciammarella, Cesar A.; Bhat, Gopalakrishna K.

1991-12-01

This paper presents a high resolution computer assisted moire technique for the measurement of displacements and strains at the microscopic level. The detection of micro-displacements using a moire grid and the problem associated with the recovery of displacement field from the sampled values of the grid intensity are discussed. A two dimensional Fourier transform method for the extraction of displacements from the image of the moire grid is outlined. An example of application of the technique to the measurement of strains and stresses in the vicinity of the crack tip in a compact tension specimen is given.

Bone-marrow densitometry: Assessment of marrow space of human vertebrae by single energy high resolution-quantitative computed tomography

International Nuclear Information System (INIS)

Peña, Jaime A.; Damm, Timo; Bastgen, Jan; Barkmann, Reinhard; Glüer, Claus C.; Thomsen, Felix; Campbell, Graeme M.

2016-01-01

Purpose: Accurate noninvasive assessment of vertebral bone marrow fat fraction is important for diagnostic assessment of a variety of disorders and therapies known to affect marrow composition. Moreover, it provides a means to correct fat-induced bias of single energy quantitative computed tomography (QCT) based bone mineral density (BMD) measurements. The authors developed new segmentation and calibration methods to obtain quantitative surrogate measures of marrow-fat density in the axial skeleton. Methods: The authors developed and tested two high resolution-QCT (HR-QCT) based methods which permit segmentation of bone voids in between trabeculae hypothesizing that they are representative of bone marrow space. The methods permit calculation of marrow content in units of mineral equivalent marrow density (MeMD). The first method is based on global thresholding and peeling (GTP) to define a volume of interest away from the transition between trabecular bone and marrow. The second method, morphological filtering (MF), uses spherical elements of different radii (0.1–1.2 mm) and automatically places them in between trabeculae to identify regions with large trabecular interspace, the bone-void space. To determine their performance, data were compared ex vivo to high-resolution peripheral CT (HR-pQCT) images as the gold-standard. The performance of the methods was tested on a set of excised human vertebrae with intact bone marrow tissue representative of an elderly population with low BMD. Results: 86% (GTP) and 87% (MF) of the voxels identified as true marrow space on HR-pQCT images were correctly identified on HR-QCT images and thus these volumes of interest can be considered to be representative of true marrow space. Within this volume, MeMD was estimated with residual errors of 4.8 mg/cm 3 corresponding to accuracy errors in fat fraction on the order of 5% both for GTP and MF methods. Conclusions: The GTP and MF methods on HR-QCT images permit noninvasive

Computer aided detection of ureteral stones in thin slice computed tomography volumes using Convolutional Neural Networks.

Science.gov (United States)

Längkvist, Martin; Jendeberg, Johan; Thunberg, Per; Loutfi, Amy; Lidén, Mats

2018-06-01

Computed tomography (CT) is the method of choice for diagnosing ureteral stones - kidney stones that obstruct the ureter. The purpose of this study is to develop a computer aided detection (CAD) algorithm for identifying a ureteral stone in thin slice CT volumes. The challenge in CAD for urinary stones lies in the similarity in shape and intensity of stones with non-stone structures and how to efficiently deal with large high-resolution CT volumes. We address these challenges by using a Convolutional Neural Network (CNN) that works directly on the high resolution CT volumes. The method is evaluated on a large data base of 465 clinically acquired high-resolution CT volumes of the urinary tract with labeling of ureteral stones performed by a radiologist. The best model using 2.5D input data and anatomical information achieved a sensitivity of 100% and an average of 2.68 false-positives per patient on a test set of 88 scans. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Comparison of high resolution computed tomography and pulmonary function tests in diagnosis of mild emphysema

International Nuclear Information System (INIS)

Kuwano, Kazuyoshi; Matsuba, Kenichi; Ikeda, Togo

1989-01-01

To assess the ability of high resolution CT scan and pulmonary function tests in detecting and grading mild emphysema, we correlated the high resolution CT scan and pulmonary function tests with the pathologic grade of emphysema and the destructive index of lung specimens from 42 patients undergoing thoracotomy for solitary pulmonary nodules. Using the high resolution CT scan, we could identify the pathologic grade of mild and moderate emphysema. By measuring diffusing capacity per unit alveolar gas volume (DLco/VA), it seemed to be possible to detect the mildest degree of alveolar destruction assessed by the destructive index, which was not detected by high resolution CT scan. The reason for these results seemed to be that we assessed the severity of emphysema by detecting the air space enlargement on high resolution CT scan images caused by the destruction of alveolar walls, which were detectable by measuring DLco/VA. We conclude that it is possible to detect mild emphysema using the combination of high resolution CT scan and pulmomary function tests. (author)

GPU-based cone beam computed tomography.

Science.gov (United States)

Noël, Peter B; Walczak, Alan M; Xu, Jinhui; Corso, Jason J; Hoffmann, Kenneth R; Schafer, Sebastian

2010-06-01

The use of cone beam computed tomography (CBCT) is growing in the clinical arena due to its ability to provide 3D information during interventions, its high diagnostic quality (sub-millimeter resolution), and its short scanning times (60 s). In many situations, the short scanning time of CBCT is followed by a time-consuming 3D reconstruction. The standard reconstruction algorithm for CBCT data is the filtered backprojection, which for a volume of size 256(3) takes up to 25 min on a standard system. Recent developments in the area of Graphic Processing Units (GPUs) make it possible to have access to high-performance computing solutions at a low cost, allowing their use in many scientific problems. We have implemented an algorithm for 3D reconstruction of CBCT data using the Compute Unified Device Architecture (CUDA) provided by NVIDIA (NVIDIA Corporation, Santa Clara, California), which was executed on a NVIDIA GeForce GTX 280. Our implementation results in improved reconstruction times from minutes, and perhaps hours, to a matter of seconds, while also giving the clinician the ability to view 3D volumetric data at higher resolutions. We evaluated our implementation on ten clinical data sets and one phantom data set to observe if differences occur between CPU and GPU-based reconstructions. By using our approach, the computation time for 256(3) is reduced from 25 min on the CPU to 3.2 s on the GPU. The GPU reconstruction time for 512(3) volumes is 8.5 s. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

Motion-compensated cone beam computed tomography using a conjugate gradient least-squares algorithm and electrical impedance tomography imaging motion data.

Science.gov (United States)

Pengpen, T; Soleimani, M

2015-06-13

Cone beam computed tomography (CBCT) is an imaging modality that has been used in image-guided radiation therapy (IGRT). For applications such as lung radiation therapy, CBCT images are greatly affected by the motion artefacts. This is mainly due to low temporal resolution of CBCT. Recently, a dual modality of electrical impedance tomography (EIT) and CBCT has been proposed, in which the high temporal resolution EIT imaging system provides motion data to a motion-compensated algebraic reconstruction technique (ART)-based CBCT reconstruction software. High computational time associated with ART and indeed other variations of ART make it less practical for real applications. This paper develops a motion-compensated conjugate gradient least-squares (CGLS) algorithm for CBCT. A motion-compensated CGLS offers several advantages over ART-based methods, including possibilities for explicit regularization, rapid convergence and parallel computations. This paper for the first time demonstrates motion-compensated CBCT reconstruction using CGLS and reconstruction results are shown in limited data CBCT considering only a quarter of the full dataset. The proposed algorithm is tested using simulated motion data in generic motion-compensated CBCT as well as measured EIT data in dual EIT-CBCT imaging. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

High-resolution photoacoustic tomography of resting-state functional connectivity in the mouse brain

OpenAIRE

Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Quentin; Culver, Joseph P.; Wang, Lihong V.

2013-01-01

The increasing use of mouse models for human brain disease studies presents an emerging need for a new functional imaging modality. Using optical excitation and acoustic detection, we developed a functional connectivity photoacoustic tomography system, which allows noninvasive imaging of resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight functional regions, including the olfactory bu...

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.

X-ray computed tomography using curvelet sparse regularization.

Science.gov (United States)

Wieczorek, Matthias; Frikel, Jürgen; Vogel, Jakob; Eggl, Elena; Kopp, Felix; Noël, Peter B; Pfeiffer, Franz; Demaret, Laurent; Lasser, Tobias

2015-04-01

Reconstruction of x-ray computed tomography (CT) data remains a mathematically challenging problem in medical imaging. Complementing the standard analytical reconstruction methods, sparse regularization is growing in importance, as it allows inclusion of prior knowledge. The paper presents a method for sparse regularization based on the curvelet frame for the application to iterative reconstruction in x-ray computed tomography. In this work, the authors present an iterative reconstruction approach based on the alternating direction method of multipliers using curvelet sparse regularization. Evaluation of the method is performed on a specifically crafted numerical phantom dataset to highlight the method's strengths. Additional evaluation is performed on two real datasets from commercial scanners with different noise characteristics, a clinical bone sample acquired in a micro-CT and a human abdomen scanned in a diagnostic CT. The results clearly illustrate that curvelet sparse regularization has characteristic strengths. In particular, it improves the restoration and resolution of highly directional, high contrast features with smooth contrast variations. The authors also compare this approach to the popular technique of total variation and to traditional filtered backprojection. The authors conclude that curvelet sparse regularization is able to improve reconstruction quality by reducing noise while preserving highly directional features.

Computed tomography for radiographers

International Nuclear Information System (INIS)

Brooker, M.

1986-01-01

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

Computer tomography in otolaryngology

International Nuclear Information System (INIS)

Gradzki, J.

1981-01-01

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

Application and development of Industrial Computed Tomography in China

International Nuclear Information System (INIS)

Kong Fangeng; Xian Wu

1996-01-01

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

Clinical Impact of Emphysema Evaluated by High-Resolution Computed Tomography on Idiopathic Pulmonary Fibrosis Diagnosed by Surgical Lung Biopsy.

Science.gov (United States)

Kohashi, Yasuo; Arai, Toru; Sugimoto, Chikatoshi; Tachibana, Kazunobu; Akira, Masanori; Kitaichi, Masanori; Hayashi, Seiji; Inoue, Yoshikazu

2016-01-01

The prognosis of combined cases of pulmonary fibrosis and emphysema is unresolved partially because radiological differentiation between usual interstitial pneumonia and nonspecific interstitial pneumonia is difficult in coexisting emphysema cases. The purpose of this study was to clarify the clinical impact of emphysema on the survival of patients with idiopathic pulmonary fibrosis (IPF). One hundred and seven patients with interstitial lung diseases were diagnosed by surgical lung biopsies between 2006 and 2012, and 47 patients were diagnosed with IPF through multidisciplinary discussion. Emphysema on high-resolution computed tomography scans was evaluated semiquantitatively by visual scoring. Eight out of the 47 IPF patients showed a higher emphysema score (>3) and were diagnosed to have IPF-emphysema. The median survival time of patients with IPF-emphysema (1,734 days) from the initial diagnosis was significantly shorter than that of patients with IPF alone (2,229 days) by Kaplan-Meier analysis (p = 0.007, log-rank test). Univariate Cox proportional hazard regression analyses revealed that a higher total emphysema score (>3.0) was a significantly poor prognostic factor in addition to Krebs von den Lungen-6, surfactant protein-D, arterial oxygen tension, percent forced vital capacity, and percent diffusing capacity of carbon monoxide (%DLCO). Multivariate Cox proportional hazard regression analyses with the stepwise method showed that higher total emphysema score (>3) and %DLCO were significantly poor prognostic factors. The prognosis of IPF-emphysema was significantly worse than that of IPF alone. © 2016 S. Karger AG, Basel.

Possible UIP pattern on high-resolution computed tomography is associated with better survival than definite UIP in IPF patients.

Science.gov (United States)

Salisbury, Margaret L; Tolle, Leslie B; Xia, Meng; Murray, Susan; Tayob, Nabihah; Nambiar, Anoop M; Schmidt, Shelley L; Lagstein, Amir; Myers, Jeffery L; Gross, Barry H; Kazerooni, Ella A; Sundaram, Baskaran; Chughtai, Aamer R; Martinez, Fernando J; Flaherty, Kevin R

2017-10-01

Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing lung disease of unknown etiology. Inter-society consensus guidelines on IPF diagnosis and management outline radiologic patterns including definite usual interstitial pneumonia (UIP), possible UIP, and inconsistent with UIP. We evaluate these diagnostic categories as prognostic markers among patients with IPF. Included subjects had biopsy-proven UIP, a multidisciplinary team diagnosis of IPF, and a baseline high-resolution computed tomography (HRCT). Thoracic radiologists assigned the radiologic pattern and documented the presence and extent of specific radiologic findings. The outcome of interest was lung transplant-free survival. IPF patients with a possible UIP pattern on HRCT had significantly longer Kaplan-Meier event-free survival compared to those with definite UIP pattern (5.21 and 3.57 years, respectively, p = 0.002). In a multivariable Cox proportional hazards model adjusted for baseline age, gender, %-predicted FVC, and %-predicted DLCO via the GAP Stage, extent of fibrosis (via the traction bronchiectasis score) and ever-smoker status, possible UIP pattern on HRCT (versus definite UIP) was associated with reduced hazard of death or lung transplant (HR = 0.42, CI 95% 0.23-0.78, p = 0.006). Radiologic diagnosis categories outlined by inter-society consensus guidelines is a widely-reported and potentially useful prognostic marker in IPF patients, with possible UIP pattern on HRCT associated with a favorable prognosis compared to definite UIP pattern, after adjusting for relevant covariates. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chest Abnormalities in Juvenile-Onset Mixed Connective Tissue Disease: Assessment with High-Resolution Computed Tomography and Pulmonary Function Tests

International Nuclear Information System (INIS)

Aaloekken, T.M.; Mynarek, G.; Kolbenstvedt, A.; Lilleby, V.; Foerre, Oe.; Soeyseth, V.; Pripp, A.H.; Johansen, B.

2009-01-01

Background: Mixed connective tissue disease (MCTD) is associated with several chest manifestations. Only a few studies have focused on chest manifestations in juvenile-onset MCTD (jMCTD), and the true prevalence of pulmonary abnormalities on high-resolution computed tomography (HRCT) in these patients is unknown. Purpose: To investigate the occurrence of pulmonary abnormalities in jMCTD with particular reference to interstitial lung disease (ILD), and to evaluate a possible association between pulmonary findings and disease-related variables. Material and Methods: Twenty-four childhood-onset MCTD patients with median disease duration of 10.5 years (range 1-21 years) were investigated in a cross-sectional study by means of HRCT, pulmonary function tests (PFT), and clinical assessment. Results: Discrete ILD was identified in six patients (25%). Median extent of ILD was 2.0%, and all except one of the patients had very mild disease in which 5% or less of the parenchyma was affected. The CT features of fibrosis were mainly microcystic and fine intralobular. The most frequently abnormal PFT was carbon monoxide uptake from the lung, which was abnormal in 33% of the patients. PFT and disease duration were not significantly associated with HRCT findings of ILD. Conclusion: The prevalence of ILD in childhood-onset MCTD patients was lower than previously believed. In most of the patients with ILD, the findings were subtle and without clinical correlation. The results suggest a low extent of ILD in childhood-onset MCTD, even after long-term disease duration

Ultra-High Resolution Optical Coherence Tomography Imaging of Unilateral Drusen in a 31 Year Old Woman.

Science.gov (United States)

de Carlo, Talisa E; Adhi, Mehreen; Lu, Chen D; Duker, Jay S; Fujimoto, James G; Waheed, Nadia K

We report a case of widespread unilateral drusen in a healthy 31 year old Caucasian woman using multi-modal imaging including ultra-high resolution optical coherence tomography (UHR-OCT). Dilated fundus exam showed multiple drusen-like lesions in the posterior pole without heme or fluid. Fundus auto fluorescence demonstrated hyperautofluorescent at the deposits. Fluorescein angiography revealed mild hyperfluorescence and staining of the lesions. Spectral-domain optical coherence tomography (SD-OCT) OS showed accumulations in the temporal macula at Bruch's membrane. UHR-OCT provided improved axial resolution compared to the standard 5 μm on the commercial SD-OCT and confirmed the presence of deposits in Bruch's membrane, consistent with drusen. The retinal layers were draped over the excrescences but did not show any disruption.

Electro-optical system for the high speed reconstruction of computed tomography images

International Nuclear Information System (INIS)

Tresp, V.

1989-01-01

An electro-optical system for the high-speed reconstruction of computed tomography (CT) images has been built and studied. The system is capable of reconstructing high-contrast and high-resolution images at video rate (30 images per second), which is more than two orders of magnitude faster than the reconstruction rate achieved by special purpose digital computers used in commercial CT systems. The filtered back-projection algorithm which was implemented in the reconstruction system requires the filtering of all projections with a prescribed filter function. A space-integrating acousto-optical convolver, a surface acoustic wave filter and a digital finite-impulse response filter were used for this purpose and their performances were compared. The second part of the reconstruction, the back projection of the filtered projections, is computationally very expensive. An optical back projector has been built which maps the filtered projections onto the two-dimensional image space using an anamorphic lens system and a prism image rotator. The reconstructed image is viewed by a video camera, routed through a real-time image-enhancement system, and displayed on a TV monitor. The system reconstructs parallel-beam projection data, and in a modified version, is also capable of reconstructing fan-beam projection data. This extension is important since the latter are the kind of projection data actually acquired in high-speed X-ray CT scanners. The reconstruction system was tested by reconstructing precomputed projection data of phantom images. These were stored in a special purpose projection memory and transmitted to the reconstruction system as an electronic signal. In this way, a projection measurement system that acquires projections sequentially was simulated

Optimised performance of industrial high resolution computerised tomography

International Nuclear Information System (INIS)

Maangaard, M.

2000-01-01

-sensitivity/noise, density-sensitivity/noise, and mass attenuation-sensitivity/noise. With these measures, a method is presented that finds the optimal equipment settings, where no improvement can be made without worsening at least one other sensitivity/noise ratio. This thesis includes modelling and verification of the sharpness of the CT system in terms of the modulation transfer function, MTF. Together with the limiting perception factor and the maximised SNR the detectability limits for any specific contrasting detail in the centre of a cylindrical sample can be determined. It is also demonstrated that the model can be used to suppress beam hardening when collecting CT-data. When homogeneous samples are imaged, the model can in addition be used to make post-processing corrections for suppressing the beam hardening artefacts. Wavelet-based local tomography has been found to produce images with good accuracy from projection data only from a small region in a sample. This technique is demonstrated on thermal barrier coatings, which contain internal cracks. With optimised equipment settings and geometrical magnification of a region in the sample, wavelet-based local tomography produced high-resolution images of excellent quality. The increased resolution reveals features in the microstructure that cannot be resolved with traditional CT. This technique will be a useful tool for characterisation of the microstructure in advanced materials

Tracking Solid Oxide Cell Microstructure Evolution by High Resolution 3D Nano-Tomography

DEFF Research Database (Denmark)

De Angelis, Salvatore

. The degradation processes are mainly attributed to morphological changes occurring within the electrodes microstructure. Therefore, precise tracking of 3D microstructural evolution during operation is considered crucial to understanding the complex relationship between microstructure and performance. In this work......, X-ray ptychographic tomography is applied to SOC materials, demonstrating unprecedented spatial resolution and data quality. The eect of a complete redox cycle on the same Ni-YSZ microstructure is visualized ex-situ in 3D, showing major rearrangement of the nickel network after reduction......, the formation of cracks in the YSZ, and void formation in nickel oxide after oxidation. Capitalizing on the high resolution of ptychography, the eect of nickel coarsening on the Ni-YSZ microstructure evolution is studied ex-situ in three dimensions, while the sample is repeatedly scanned and treated at high...

A new method for measuring temporal resolution in electrocardiogram-gated reconstruction image with area-detector computed tomography

International Nuclear Information System (INIS)

Kaneko, Takeshi; Takagi, Masachika; Kato, Ryohei; Anno, Hirofumi; Kobayashi, Masanao; Yoshimi, Satoshi; Sanda, Yoshihiro; Katada, Kazuhiro

2012-01-01

The purpose of this study was to design and construct a phantom for using motion artifact in the electrocardiogram (ECG)-gated reconstruction image. In addition, the temporal resolution under various conditions was estimated. A stepping motor was used to move the phantom over an arc in a reciprocating manner. The program for controlling the stepping motor permitted the stationary period and the heart rate to be adjusted as desired. Images of the phantom were obtained using a 320-row area-detector computed tomography (ADCT) system under various conditions using the ECG-gated reconstruction method. For estimation, the reconstruction phase was continuously changed and the motion artifacts were quantitatively assessed. The temporal resolution was calculated from the number of motion-free images. Changes in the temporal resolution according to heart rate, rotation time, the number of reconstruction segments and acquisition position in z-axis were also investigated. The measured temporal resolution of ECG-gated half reconstruction is 180 ms, which is in good agreement with the nominal temporal resolution of 175 ms. The measured temporal resolution of ECG-gated segmental reconstruction is in good agreement with the nominal temporal resolution in most cases. The estimated temporal resolution improved to approach the nominal temporal resolution as the number of reconstruction segments was increased. Temporal resolution in changing acquisition position is equal. This study shows that we could design a new phantom for estimating temporal resolution. (author)

Computed Tomography (CT) -- Head

Medline Plus

Full Text Available ... When the image slices are reassembled by computer software, the result is a very detailed multidimensional view ... Safety Images related to Computed Tomography (CT) - Head Videos related to Computed Tomography (CT) - Head Sponsored by ...

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

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

Quantification in single photon emission computed tomography (SPECT)

International Nuclear Information System (INIS)

Buvat, Irene

2005-01-01

The objective of this lecture is to understand the possibilities and limitations of the quantitative analysis of single photon emission computed tomography (SPECT) images. It is also to identify the conditions to be fulfilled to obtain reliable quantitative measurements from images. Content: 1 - Introduction: Quantification in emission tomography - definition and challenges; quantification biasing phenomena; 2 - quantification in SPECT, problems and correction methods: Attenuation, scattering, un-stationary spatial resolution, partial volume effect, movement, tomographic reconstruction, calibration; 3 - Synthesis: actual quantification accuracy; 4 - Beyond the activity concentration measurement

Mesenteric panniculitis: computed tomography aspects

International Nuclear Information System (INIS)

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

2001-01-01

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

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... Site Index A-Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses ... of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

Full Text Available ... Z Children's (Pediatric) CT (Computed Tomography) Pediatric computed tomography (CT) is a fast, painless exam that uses special ... the limitations of Children's CT? What is Children's CT? Computed tomography, more commonly known as a CT or CAT ...

Computed tomography in the evaluation of thyroid disease

International Nuclear Information System (INIS)

Silverman, P.M.; Newman, G.E.; Korobkin, M.; Workman, J.B.; Moore, A.V.; Coleman, R.E.

1984-01-01

Traditionally, thyroid imaging has been performed primarily using radionuclide scanning. High-resolution computed tomography (CT) was performed in 18 patients to evaluate the CT appearance of various thyroid abnormalities including diffuse toxic goiter, multinodular goiter, Hashimoto thyroiditis, thyroid adenoma, and malignant thyroid tumors. CT images of the thyroid were correlated with radionuclide scanning, surgical findings, and clinical and laboratory results. CT provided a complementary method for evaluation of the thyroid by defining the morphology of the thyroid gland and more precisely defining the anatomic extent of thyroid abnormalities in relation to the normal structures of the neck and mediastinum

Computed tomography in the evaluation of thyroid disease

Energy Technology Data Exchange (ETDEWEB)

Silverman, P.M.; Newman, G.E.; Korobkin, M.; Workman, J.B.; Moore, A.V.; Coleman, R.E.

1984-05-01

Traditionally, thyroid imaging has been performed primarily using radionuclide scanning. High-resolution computed tomography (CT) was performed in 18 patients to evaluate the CT appearance of various thyroid abnormalities including diffuse toxic goiter, multinodular goiter, Hashimoto thyroiditis, thyroid adenoma, and malignant thyroid tumors. CT images of the thyroid were correlated with radionuclide scanning, surgical findings, and clinical and laboratory results. CT provided a complementary method for evaluation of the thyroid by defining the morphology of the thyroid gland and more precisely defining the anatomic extent of thyroid abnormalities in relation to the normal structures of the neck and mediastinum.

Variation in the human ribs geometrical properties and mechanical response based on X-ray computed tomography images resolution.

Science.gov (United States)

Perz, Rafał; Toczyski, Jacek; Subit, Damien

2015-01-01

Computational models of the human body are commonly used for injury prediction in automobile safety research. To create these models, the geometry of the human body is typically obtained from segmentation of medical images such as computed tomography (CT) images that have a resolution between 0.2 and 1mm/pixel. While the accuracy of the geometrical and structural information obtained from these images depend greatly on their resolution, the effect of image resolution on the estimation of the ribs geometrical properties has yet to be established. To do so, each of the thirty-four sections of ribs obtained from a Post Mortem Human Surrogate (PMHS) was imaged using three different CT modalities: standard clinical CT (clinCT), high resolution clinical CT (HRclinCT), and microCT. The images were processed to estimate the rib cross-section geometry and mechanical properties, and the results were compared to those obtained from the microCT images by computing the 'deviation factor', a metric that quantifies the relative difference between results obtained from clinCT and HRclinCT to those obtained from microCT. Overall, clinCT images gave a deviation greater than 100%, and were therefore deemed inadequate for the purpose of this study. HRclinCT overestimated the rib cross-sectional area by 7.6%, the moments of inertia by about 50%, and the cortical shell area by 40.2%, while underestimating the trabecular area by 14.7%. Next, a parametric analysis was performed to quantify how the variations in the estimate of the geometrical properties affected the rib predicted mechanical response under antero-posterior loading. A variation of up to 45% for the predicted peak force and up to 50% for the predicted stiffness was observed. These results provide a quantitative estimate of the sensitivity of the response of the FE model to the resolution of the images used to generate it. They also suggest that a correction factor could be derived from the comparison between microCT and

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-02-15

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

Fast iterative segmentation of high resolution medical images

International Nuclear Information System (INIS)

Hebert, T.J.

1996-01-01

Various applications in positron emission tomography (PET), single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) require segmentation of 20 to 60 high resolution images of size 256x256 pixels in 3-9 seconds per image. This places particular constraints on the design of image segmentation algorithms. This paper examines the trade-offs in segmenting images based on fitting a density function to the pixel intensities using curve-fitting versus the maximum likelihood method. A quantized data representation is proposed and the EM algorithm for fitting a finite mixture density function to the quantized representation for an image is derived. A Monte Carlo evaluation of mean estimation error and classification error showed that the resulting quantized EM algorithm dramatically reduces the required computation time without loss of accuracy

Noninvasive coronary angioscopy using electron beam computed tomography and multidetector computed tomography

NARCIS (Netherlands)

van Ooijen, PMA; Nieman, K; de Feyter, PJ; Oudkerk, M

2002-01-01

With the advent of noninvasive coronary imaging techniques like multidetector computed tomography and electron beam computed tomography, new representation methods such as intracoronary visualization. have been introduced. We explore the possibilities of these novel visualization techniques and

Vascular channels in metacarpophalangeal joints : a comparative histologic and high-resolution imaging study

NARCIS (Netherlands)

Scharmga, A.; Keller, K.K.; Peters, M.; van Tubergen, A.; van den Bergh, J.P.W.; van Rietbergen, B.; Weijers, R.; Loeffen, D.; Hauge, E.M.; Geusens, P.P.M.M.

2017-01-01

We evaluated whether cortical interruptions classified as vascular channel (VC) on high-resolution peripheral quantitative computed tomography (HR-pQCT) could be confirmed by histology. We subsequently evaluated the image characteristics of histologically identified VCs on matched single and

High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumonia

International Nuclear Information System (INIS)

Marchiori, Edson; Zanetti, Glaucia; Hochhegger, Bruno; Rodrigues, Rosana Souza; Fontes, Cristina Asvolinsque Pantaleao; Nobre, Luiz Felipe; Dias Mancano, Alexandre; Meirelles, Gustavo; Irion, Klaus Loureiro

2010-01-01

Objective: The aim of this study was to assess the high-resolution computed tomography (HRCT) findings at presentation in patients diagnosed with Influenza A (H1N1) virus-associated pneumonia. Materials and methods: We reviewed the HRCT findings from 20 patients diagnosed with Influenza A (H1N1) and compared their HRCT scans with chest radiographs, obtained on the same day. The imaging studies were obtained 4-9 days after the onset of symptoms. The patients included 11 men and 9 women (ages 24-62 years; mean 42.7 years). All patients had a body temperature greater than 100.4 deg. F (>38 deg. C), tachypnea, and cough. Other common symptoms included diarrhea (60%) and sore throat (30%). The radiographs and HRCT scans were reviewed independently by two observers who reached a consensus decision. Results: The predominant HRCT findings consisted of bilateral ground-glass opacities (n = 12), bilateral areas of consolidation (n = 2), or a mixed bilateral pattern of ground-glass opacities and areas of consolidation (n = 6). The abnormalities were bilateral in all of the 20 patients, had a predominantly sub-pleural distribution in 13 patients, and had a random distribution in the remaining 7 patients. The predominant radiographic findings were consolidations. Normal radiographs were found in 4 out of the 20 patients. Conclusion: HRCT may reveal parenchymal abnormalities in patients with Influenza A (H1N1) infection who have normal findings on radiographs. The predominant HRCT findings were bilateral, peripheral, ground-glass opacities and/or bilateral areas of consolidation. The patients who presented consolidations had more severe clinical course.

High-resolution computed tomography findings from adult patients with Influenza A (H1N1) virus-associated pneumonia

Energy Technology Data Exchange (ETDEWEB)

Marchiori, Edson [Fluminense Federal University, Rio de Janeiro (Brazil); Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)], E-mail: edmarchiori@gmail.com; Zanetti, Glaucia [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)], E-mail: glauciazanetti@gmail.com; Hochhegger, Bruno [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil)], E-mail: brunohochhegger@gmail.com; Rodrigues, Rosana Souza [Federal University of Rio de Janeiro, Rio de Janeiro (Brazil); D' OR Institute for Research and Education, Rio de Janeiro (Brazil)], E-mail: rosana.souzarodrigues@gmail.com; Fontes, Cristina Asvolinsque Pantaleao [Fluminense Federal University, Rio de Janeiro (Brazil)], E-mail: cristinasvolinsque@gmail.com; Nobre, Luiz Felipe [Santa Catarina Federal University, Florianopolis (Brazil)], E-mail: luizfelipenobresc@gmail.com; Dias Mancano, Alexandre [Anchieta Hospital, Taguatinga, DF (Brazil)], E-mail: alex.manzano1@gmail.com; Meirelles, Gustavo [Sao Paulo Federal University, Sao Paulo (Brazil)], E-mail: gmeirelles@gmail.com; Irion, Klaus Loureiro [Liverpool Heart and Chest Hospital NHS Trust, Liverpool (United Kingdom); Royal Liverpool and Broadgreen University Hospital NHS, Liverpool (United Kingdom)], E-mail: klaus.irion@btinternet.com

2010-04-15

Objective: The aim of this study was to assess the high-resolution computed tomography (HRCT) findings at presentation in patients diagnosed with Influenza A (H1N1) virus-associated pneumonia. Materials and methods: We reviewed the HRCT findings from 20 patients diagnosed with Influenza A (H1N1) and compared their HRCT scans with chest radiographs, obtained on the same day. The imaging studies were obtained 4-9 days after the onset of symptoms. The patients included 11 men and 9 women (ages 24-62 years; mean 42.7 years). All patients had a body temperature greater than 100.4 deg. F (>38 deg. C), tachypnea, and cough. Other common symptoms included diarrhea (60%) and sore throat (30%). The radiographs and HRCT scans were reviewed independently by two observers who reached a consensus decision. Results: The predominant HRCT findings consisted of bilateral ground-glass opacities (n = 12), bilateral areas of consolidation (n = 2), or a mixed bilateral pattern of ground-glass opacities and areas of consolidation (n = 6). The abnormalities were bilateral in all of the 20 patients, had a predominantly sub-pleural distribution in 13 patients, and had a random distribution in the remaining 7 patients. The predominant radiographic findings were consolidations. Normal radiographs were found in 4 out of the 20 patients. Conclusion: HRCT may reveal parenchymal abnormalities in patients with Influenza A (H1N1) infection who have normal findings on radiographs. The predominant HRCT findings were bilateral, peripheral, ground-glass opacities and/or bilateral areas of consolidation. The patients who presented consolidations had more severe clinical course.

Bone-marrow densitometry: Assessment of marrow space of human vertebrae by single energy high resolution-quantitative computed tomography

Energy Technology Data Exchange (ETDEWEB)

Peña, Jaime A.; Damm, Timo; Bastgen, Jan; Barkmann, Reinhard; Glüer, Claus C., E-mail: glueer@rad.uni-kiel.de [Sektion Biomedizinische Bildgebung, Klinik für Radiologie und Neuroradiologie, Christian-Albrechts-Universität zu Kiel, Campus Kiel, Kiel 24118 (Germany); Thomsen, Felix [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Sur, Bahía Blanca 8000 (Argentina); Campbell, Graeme M. [Sektion Biomedizinische Bildgebung, Klinik für Radiologie und Neuroradiologie, Christian-Albrechts-Universität zu Kiel, Campus Kiel, Kiel 24118, Germany and Institut für Biomechanik, Technische Universität Hamburg-Harburg (TUHH), Hamburg 21073 (Germany)

2016-07-15

Purpose: Accurate noninvasive assessment of vertebral bone marrow fat fraction is important for diagnostic assessment of a variety of disorders and therapies known to affect marrow composition. Moreover, it provides a means to correct fat-induced bias of single energy quantitative computed tomography (QCT) based bone mineral density (BMD) measurements. The authors developed new segmentation and calibration methods to obtain quantitative surrogate measures of marrow-fat density in the axial skeleton. Methods: The authors developed and tested two high resolution-QCT (HR-QCT) based methods which permit segmentation of bone voids in between trabeculae hypothesizing that they are representative of bone marrow space. The methods permit calculation of marrow content in units of mineral equivalent marrow density (MeMD). The first method is based on global thresholding and peeling (GTP) to define a volume of interest away from the transition between trabecular bone and marrow. The second method, morphological filtering (MF), uses spherical elements of different radii (0.1–1.2 mm) and automatically places them in between trabeculae to identify regions with large trabecular interspace, the bone-void space. To determine their performance, data were compared ex vivo to high-resolution peripheral CT (HR-pQCT) images as the gold-standard. The performance of the methods was tested on a set of excised human vertebrae with intact bone marrow tissue representative of an elderly population with low BMD. Results: 86% (GTP) and 87% (MF) of the voxels identified as true marrow space on HR-pQCT images were correctly identified on HR-QCT images and thus these volumes of interest can be considered to be representative of true marrow space. Within this volume, MeMD was estimated with residual errors of 4.8 mg/cm{sup 3} corresponding to accuracy errors in fat fraction on the order of 5% both for GTP and MF methods. Conclusions: The GTP and MF methods on HR-QCT images permit noninvasive

Computed Tomography (CT) -- Head

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

High spatial resolution CT image reconstruction using parallel computing

International Nuclear Information System (INIS)

Yin Yin; Liu Li; Sun Gongxing

2003-01-01

Using the PC cluster system with 16 dual CPU nodes, we accelerate the FBP and OR-OSEM reconstruction of high spatial resolution image (2048 x 2048). Based on the number of projections, we rewrite the reconstruction algorithms into parallel format and dispatch the tasks to each CPU. By parallel computing, the speedup factor is roughly equal to the number of CPUs, which can be up to about 25 times when 25 CPUs used. This technique is very suitable for real-time high spatial resolution CT image reconstruction. (authors)

The Dimensions of the Orbital Cavity Based on High-Resolution Computed Tomography of Human Cadavers

DEFF Research Database (Denmark)

Felding, Ulrik Ascanius; Bloch, Sune Land; Buchwald, Christian von

2016-01-01

for surface area. To authors' knowledge, this study is the first to have measured the entire surface area of the orbital cavity.The volume and surface area of the orbital cavity were estimated in computed tomography scans of 11 human cadavers using unbiased stereological sampling techniques. The mean (± SD......) total volume and total surface area of the orbital cavities was 24.27 ± 3.88 cm and 32.47 ± 2.96 cm, respectively. There was no significant difference in volume (P = 0.315) or surface area (P = 0.566) between the 2 orbital cavities.The stereological technique proved to be a robust and unbiased method...... that may be used as a gold standard for comparison with automated computer software. Future imaging studies in blow-out fracture patients may be based on individual and relative calculation involving both herniated volume and fractured surface area in relation to the total volume and surface area...

In vivo quantitative assessment of myocardial structure, function, perfusion and viability using cardiac micro-computed tomography

NARCIS (Netherlands)

E.D. van Deel (Elza); Y. Ridwan (Yanto); van Vliet, J.N. (J. Nicole); Belenkov, S. (Sasha); J. Essers (Jeroen)

2016-01-01

textabstractThe use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most

Emission computed tomography

International Nuclear Information System (INIS)

Budinger, T.F.; Gullberg, G.T.; Huesman, R.H.

1979-01-01

This chapter is devoted to the methods of computer assisted tomography for determination of the three-dimensional distribution of gamma-emitting radionuclides in the human body. The major applications of emission computed tomography are in biological research and medical diagnostic procedures. The objectives of these procedures are to make quantitative measurements of in vivo biochemical and hemodynamic functions

High-resolution computed tomography of the temporal bone. Part 1.: normal anatomy

International Nuclear Information System (INIS)

Grzegorzewski, M.; Boron, Z.; Burzynska-Makuch, M.

1995-01-01

Normal anatomy of the temporal bone in transverse and coronal sections was presented. CT studies were performed using high-resolution program. The images of an asymptomatic ear of 2 patients were selected from 68 cases examined on account of various otological diseases. All the sections showed as many as 68 anatomic structures. (author)

What is Computed Tomography?

Science.gov (United States)

... Imaging Medical X-ray Imaging What is Computed Tomography? Share Tweet Linkedin Pin it More sharing options ... Chest X ray Image back to top Computed Tomography (CT) Although also based on the variable absorption ...

High-resolution computed tomography of the lung in smokers: Visual and computer-based analysis

International Nuclear Information System (INIS)

Mueller-Leisse, C.; Otto, A.; Berger, F.; Schmitz, E.; Guenther, R.W.

1997-01-01

Purpose: It has been the aim of the study to assess parenchymal changes in the lung with high-resolution CT in healthy heavy, moderate, and non-smokers. Material and methods: We prospectively evaluated CT changes in 42 healthy heavy smokers (gr. (group) 2, ≥30 pack-years), 40 moderate smokers (gr. 1, R , Kontron GmbH, Munich, Germany). Results: Productive cough, dyspnoea and chronic bronchitis were more common in smokers than in non-smokers (p [de

Diagnostic accuracy for X-ray chest in interstitial lung disease as confirmed by high resolution computed tomography (HRCT) chest

International Nuclear Information System (INIS)

Afzal, F.; Raza, S.; Shafique, M.

2017-01-01

Objective: To determine the diagnostic accuracy of x-ray chest in interstitial lung disease as confirmed by high resolution computed tomography (HRCT) chest. Study Design: A cross-sectional validational study. Place and Duration of Study: Department of Diagnostic Radiology, Combined Military Hospital Rawalpindi, from Oct 2013 to Apr 2014. Material and Method: A total of 137 patients with clinical suspicion of interstitial lung disease (ILD) aged 20-50 years of both genders were included in the study. Patients with h/o previous histopathological diagnosis, already taking treatment and pregnant females were excluded. All the patients had chest x-ray and then HRCT. The x-ray and HRCT findings were recorded as presence or absence of the ILD. Results: Mean age was 40.21 ± 4.29 years. Out of 137 patients, 79 (57.66 percent) were males and 58 (42.34 percent) were females with male to female ratio of 1.36:1. Chest x-ray detected ILD in 80 (58.39 percent) patients, out of which, 72 (true positive) had ILD and 8 (false positive) had no ILD on HRCT. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of chest x-ray in diagnosing ILD was 80.0 percent, 82.98 percent, 90.0 percent, 68.42 percent and 81.02 percent respectively. Conclusion: This study concluded that chest x-ray is simple, non-invasive, economical and readily available alternative to HRCT with an acceptable diagnostic accuracy of 81 percent in the diagnosis of ILD. (author)

Identifying the most infectious lesions in pulmonary tuberculosis by high-resolution multi-detector computed tomography

International Nuclear Information System (INIS)

Yeh, Jun Jun; Chen, Solomon Chih-Cheng; Teng, Wen-Bao; Chou, Chun-Hsiung; Hsieh, Shih-Peng; Lee, Tsung-Lung; Wu, Ming-Ting

2010-01-01

This study aimed to determine whether characteristics detected by multi-detector computed tomography (MDCT) were predictive of highly infectious, smear-positive, active pulmonary tuberculosis (PTB). Among 124 patients with active PTB, 84 had positive (group 1) and 40 had negative (group 2) smear results for acid-fast bacilli. Multiplanar MDCT, axial conventional CT and chest X-ray images were analysed retrospectively for morphology, number, and segmental (lobe) distribution of lesions. By multivariate analysis, consolidation over any segment of the upper, middle, or lingual lobes, cavitations, and clusters of nodules were associated with group 1, while centrilobular nodules were predictive of group 2. Using five independent variables associated with risk in group 1, a prediction model was created to distinguish between group 1 and group 2. ROC curve analysis showed an area under the curve of 0.951 ± 0.021 for this prediction model. With the ideal cutoff point score of 1, the sensitivity, specificity, and positive predictive values were 84.5%, 97.5%, and 98.0%, respectively. A model to predict smear-positive active PTB on the basis of findings from MDCT may be a useful tool for clinical decisions about isolating patients pending sputum smear results. (orig.)

Identifying the most infectious lesions in pulmonary tuberculosis by high-resolution multi-detector computed tomography

Energy Technology Data Exchange (ETDEWEB)

Yeh, Jun Jun [Pingtung Christian Hospital, Pingtung (China); Mei-Ho Institute of Technology, Pingtung (China); China Medical University, Taichung (China); Chen, Solomon Chih-Cheng [Pingtung Christian Hospital, Pingtung (China); National Taiwan University, Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, Taipei (China); Teng, Wen-Bao; Chou, Chun-Hsiung; Hsieh, Shih-Peng; Lee, Tsung-Lung [Pingtung Christian Hospital, Pingtung (China); Wu, Ming-Ting [National Yang Ming University, Faculty of Medicine, School of Medicine, Taipei (China); Kaohsiung Veterans General Hospital, Section of Thoracic and Circulation Imaging, Department of Radiology, Kaohsiung (China)

2010-09-15

This study aimed to determine whether characteristics detected by multi-detector computed tomography (MDCT) were predictive of highly infectious, smear-positive, active pulmonary tuberculosis (PTB). Among 124 patients with active PTB, 84 had positive (group 1) and 40 had negative (group 2) smear results for acid-fast bacilli. Multiplanar MDCT, axial conventional CT and chest X-ray images were analysed retrospectively for morphology, number, and segmental (lobe) distribution of lesions. By multivariate analysis, consolidation over any segment of the upper, middle, or lingual lobes, cavitations, and clusters of nodules were associated with group 1, while centrilobular nodules were predictive of group 2. Using five independent variables associated with risk in group 1, a prediction model was created to distinguish between group 1 and group 2. ROC curve analysis showed an area under the curve of 0.951 {+-} 0.021 for this prediction model. With the ideal cutoff point score of 1, the sensitivity, specificity, and positive predictive values were 84.5%, 97.5%, and 98.0%, respectively. A model to predict smear-positive active PTB on the basis of findings from MDCT may be a useful tool for clinical decisions about isolating patients pending sputum smear results. (orig.)

Initial evaluation of image performance of a 3-D x-ray system: phantom-based comparison of 3-D tomography with conventional computed tomography.

Science.gov (United States)

Benz, Robyn Melanie; Garcia, Meritxell Alzamora; Amsler, Felix; Voigt, Johannes; Fieselmann, Andreas; Falkowski, Anna Lucja; Stieltjes, Bram; Hirschmann, Anna

2018-01-01

Phantom-based initial performance assessment of a prototype three-dimensional (3-D) x-ray system and comparison of 3-D tomography with computed tomography (CT) were proposed. A 3-D image quality phantom was scanned with a prototype version of 3-D cone-beam CT imaging implemented on a twin robotic x-ray system using three trajectories (163 deg = table, 188 deg = upright, and 200 deg = side), six tube voltages (60, 70, 81, 90, 100, and 121 kV), and four detector doses (0.348, 0.696, 1.740, and [Formula: see text]). CT was obtained with a clinical protocol. Spatial resolution (line pairs/cm) and soft-tissue-contrast resolution were assessed by two independent readers. Radiation dose was assessed. Descriptive and analysis of variance (ANOVA) ([Formula: see text]) were performed. With 3-D tomography, a maximum of 16 lp/cm was visible and best soft-tissue-contrast resolution was 2 mm at 30 Hounsfield units (HU) for 160 projections. With CT, 10 lp/cm was visible and soft-tissue-contrast resolution was 4 mm at 20 HU. The upright trajectory yielded significantly better spatial resolution and soft tissue contrast, and the side trajectory yielded significantly higher soft tissue contrast than the table trajectory ([Formula: see text]). Radiation dose was higher in 3-D tomography (45 to 704 mGycm) than CT (44 mGycm). Three-dimensional tomography renders overall equal or higher spatial resolution and comparable soft tissue contrast to CT for medium- and high-dose protocols in the side and upright trajectories, but with higher radiation doses.

Tropical pulmonary eosinophilia: a comparative evaluation of plain chest radiography and computed tomography

Energy Technology Data Exchange (ETDEWEB)

Sandhu Manavijit; Mukhopadhyay Sima; Sharma, S.K. [All India Inst. of Medical Sciences, New Delhi (India). Dept. of Nuclear Medicine

1996-02-01

Plain chest radiography and computed tomography (CT) of the chest were performed on 10 patients with tropical pulmonary eosinophilia (TPE). Chest radiographs revealed bilateral diffuse lesions in the lungs of all the patients with relative sparing of lower lobes in one patient. However, computed tomography revealed bilateral diffuse lung lesions in all of the patients with relative sparing of lower lobes in three patients. In seven (70%) of the 10 patients, CT provided additional information. Computed tomography was found to be superior for the detection of reticulonodular pattern, bronchiectasis, air trapping, calcification and mediastinal adenopathy. No correlation was found between pulmonary function and gas exchange data using CT densities. There was also no correlation between the absolute eosinophil count (AEC) and the radiological severity of lesions. In six patients, high-resolution CT (HRCT) was performed in addition to conventional CT (CCT), and nodularity of lesions was better appreciated in these patients. It is concluded from this study that CT is superior to plain radiography for the evaluation of patients with TPE. 17 refs., 2 tabs., 4 figs.

High-resolution breast tomography at high energy: a feasibility study of phase contrast imaging on a whole breast

International Nuclear Information System (INIS)

Sztrókay, A; Schlossbauer, T; Bamberg, F; Reiser, M F; Coan, P; Diemoz, P C; Brun, E; Bravin, A; Mayr, D

2012-01-01

Previous studies on phase contrast imaging (PCI) mammography have demonstrated an enhancement of breast morphology and cancerous tissue visualization compared to conventional imaging. We show here the first results of the PCI analyser-based imaging (ABI) in computed tomography (CT) mode on whole and large (>12 cm) tumour-bearing breast tissues. We demonstrate in this work the capability of the technique of working at high x-ray energies and producing high-contrast images of large and complex specimens. One entire breast of an 80-year-old woman with invasive ductal cancer was imaged using ABI-CT with monochromatic 70 keV x-rays and an area detector of 92×92 µm 2 pixel size. Sagittal slices were reconstructed from the acquired data, and compared to corresponding histological sections. Comparison with conventional absorption-based CT was also performed. Five blinded radiologists quantitatively evaluated the visual aspects of the ABI-CT images with respect to sharpness, soft tissue contrast, tissue boundaries and the discrimination of different structures/tissues. ABI-CT excellently depicted the entire 3D architecture of the breast volume by providing high-resolution and high-contrast images of the normal and cancerous breast tissues. These results are an important step in the evolution of PCI-CT towards its clinical implementation. (paper)

High-resolution breast tomography at high energy: a feasibility study of phase contrast imaging on a whole breast

Science.gov (United States)

Sztrókay, A.; Diemoz, P. C.; Schlossbauer, T.; Brun, E.; Bamberg, F.; Mayr, D.; Reiser, M. F.; Bravin, A.; Coan, P.

2012-05-01

Previous studies on phase contrast imaging (PCI) mammography have demonstrated an enhancement of breast morphology and cancerous tissue visualization compared to conventional imaging. We show here the first results of the PCI analyser-based imaging (ABI) in computed tomography (CT) mode on whole and large (>12 cm) tumour-bearing breast tissues. We demonstrate in this work the capability of the technique of working at high x-ray energies and producing high-contrast images of large and complex specimens. One entire breast of an 80-year-old woman with invasive ductal cancer was imaged using ABI-CT with monochromatic 70 keV x-rays and an area detector of 92×92 µm2 pixel size. Sagittal slices were reconstructed from the acquired data, and compared to corresponding histological sections. Comparison with conventional absorption-based CT was also performed. Five blinded radiologists quantitatively evaluated the visual aspects of the ABI-CT images with respect to sharpness, soft tissue contrast, tissue boundaries and the discrimination of different structures/tissues. ABI-CT excellently depicted the entire 3D architecture of the breast volume by providing high-resolution and high-contrast images of the normal and cancerous breast tissues. These results are an important step in the evolution of PCI-CT towards its clinical implementation.

Quantification of lung fibrosis and emphysema in mice using automated micro-computed tomography.

Directory of Open Access Journals (Sweden)

Ellen De Langhe

Full Text Available BACKGROUND: In vivo high-resolution micro-computed tomography allows for longitudinal image-based measurements in animal models of lung disease. The combination of repetitive high resolution imaging with fully automated quantitative image analysis in mouse models of lung fibrosis lung benefits preclinical research. This study aimed to develop and validate such an automated micro-computed tomography analysis algorithm for quantification of aerated lung volume in mice; an indicator of pulmonary fibrosis and emphysema severity. METHODOLOGY: Mice received an intratracheal instillation of bleomycin (n = 8, elastase (0.25 U elastase n = 9, 0.5 U elastase n = 8 or saline control (n = 6 for fibrosis, n = 5 for emphysema. A subset of mice was scanned without intervention, to evaluate potential radiation-induced toxicity (n = 4. Some bleomycin-instilled mice were treated with imatinib for proof of concept (n = 8. Mice were scanned weekly, until four weeks after induction, when they underwent pulmonary function testing, lung histology and collagen quantification. Aerated lung volumes were calculated with our automated algorithm. PRINCIPAL FINDINGS: Our automated image-based aerated lung volume quantification method is reproducible with low intra-subject variability. Bleomycin-treated mice had significantly lower scan-derived aerated lung volumes, compared to controls. Aerated lung volume correlated with the histopathological fibrosis score and total lung collagen content. Inversely, a dose-dependent increase in lung volume was observed in elastase-treated mice. Serial scanning of individual mice is feasible and visualized dynamic disease progression. No radiation-induced toxicity was observed. Three-dimensional images provided critical topographical information. CONCLUSIONS: We report on a high resolution in vivo micro-computed tomography image analysis algorithm that runs fully automated and allows quantification of aerated lung volume in mice. This

High resolution 3D laboratory x-ray tomography data of femora from young, 1–14 day old C57BL/6 mice

Directory of Open Access Journals (Sweden)

Emely L. Bortel

2015-09-01

Full Text Available This data article contains high resolution (1.2 µm effective pixel size lab-based micro-computed tomography (µCT reconstructed volume data of the femoral mid-shafts from young C57BL/6 mice. This data formed the basis for the analyses of bone structural development in healthy mice, including closed and open porosity as reported in Bortel et al. [1]. The data reveals changes seen in bone material and porosity distribution observed when mouse bones transform from porous scaffolds into solid structures during normal organogenesis.

Multislice computed tomography coronary angiography

NARCIS (Netherlands)

F. Cademartiri (Filippo)

2005-01-01

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

Computed tomography diagnosis of hepatocellular carcinoma rupture haemorrhage

International Nuclear Information System (INIS)

Zhi Weike; Jiang Bin; Liu Jinquan; Li Sixia; Zhu Zhichang

2004-01-01

Objective: To evaluate the diagnostic value of hepatocellular carcinoma rupture hemorrhage using Computed Tomography. Methods: Six cases diagnosed hepatocellular carcinoma rupture hemorrhage were analyzed by morphic and histologic method and investigated the key point of scan in diagnosis. Result: The correct rate of hepatocellular carcinoma rupture hemorrhage by Computed Tomography is above 83 percent, it characteristic representation is strip and would high-density shadow after enhancement. Conclusion: The characteristic representation of hepatocellular carcinoma rupture hemorrhage is attain by Computed Tomography, which provides effective operation evidences for clinical operation. (authors)

64 multislice computed tomography imaging of coronary artery origin anomalies in adults

International Nuclear Information System (INIS)

Dai Qinyi; Lv Biao; Zhang Zhaoqi

2006-01-01

Objective: To assess the value of 64 multislice computed tomography (64 MSCT) in the evaluation of coronary artery origin anomalies in adults. Methods: Nine hundred and seventy eight Chinese adult patients undergone coronary artery CT angiography (CTA) between March and July 2005 at Anzhen hospital were reviewed for this study. Results: In consecutive 978 patients, 64 MSCT identified (3.07%) with an anomalous origin of the coronary artery, in 30 patients including anomalous origin of the right coronary artery (RCA) in 9 patients, the left coronary artery (LCA)in 7 patients, both RCA and LCA in 2 patients, the absence of the left circumflex artery (LCX) in 1 patient and anomalous origin of the branch of coronary artery in 11 patients. Conclusion: Noninvasive 64 multislice computed tomography can detect the anomalous origin of the coronary artery with high resolution. (authors)

High contrast enhancement aspect of dynamic computed tomography with arterial infusion - DCT-AI

International Nuclear Information System (INIS)

Kato, Seishi; Iwasaki, Naoya; Matsumura, Yoshimitsu; Kuramae, Shigeru; Mishiro, Tadashi

1983-01-01

Dynamic computed tomography was performed on 112 cases possibly having hepatic tumors with intraarterial infusion of undiluted contrast into a selectively placed catheter following angiographies. Our dynamic program could evaluate not only early phase of enhancement but also late phase up to 120 sec. Reconstructed views from early scans and magnified views were very useful to evaluate minute sequential changes. Hepatic masses less than 5 cm in size were found in thirty-one cases. Patterns of tumor enhancement and time-density curves have been analysed to correlate them with histology. Four types of tumor enhancement were noted: (1) homogeneous (2) patchy (3) mottled (4) ringed. Characteristic changes were observed in hepatocellular carcinoma - HCC - (mostly mottled) and haemangioma (mostly patchy). The former was divided in two groups reflecting the cellular maturity. The metastatic tumor could be enhanced in a ringed form with dendritic pattern of supplying vascularities in some cases. To support the use of undiluted contrast and to investigate the diagnostic efficacy of high contrast enhancement, experiments were performed by taking transaxial views of an acrylic phantom immersed in different concentrations of contrast. Analysis of CT images taken at different HU values ranging from 0 to 450 demonstrated that the higher the concentration of contrast, the better the spatial resolution was. Also larger magnification could be expected by using higher concentration of contrast. Although our Dynamic Computed Tomography with Arterial Infusion of Contrast still has drawbacks and limited indications, we advocate it as a better way of enhancement to detect and evaluate the hepatic masses, which sometimes elude the examiner's grasp with conventional way of enhancement. (author)

High-resolution computed tomography findings of early mucinous adenocarcinomas and their pathologic characteristics in 22 surgically resected cases

Energy Technology Data Exchange (ETDEWEB)

Miyata, Naoko, E-mail: n.miyata@scchr.jp [Division of Thoracic Surgery, Shizuoka Cancer Center Hospital, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka 411-8777 (Japan); Endo, Masahiro [Division of Diagnostic Radiology, Shizuoka Cancer Center Hospital (Japan); Nakajima, Takashi [Division of Pathology, Shizuoka Cancer Center Hospital (Japan); Kojima, Hideaki; Maniwa, Tomohiro; Takahashi, Shoji; Isaka, Mitsuhiro [Division of Thoracic Surgery, Shizuoka Cancer Center Hospital, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka 411-8777 (Japan); Kameya, Toru [Division of Pathology, Shizuoka Cancer Center Hospital (Japan); Ohde, Yasuhisa [Division of Thoracic Surgery, Shizuoka Cancer Center Hospital, 1007 Shimonagakubo, Nagaizumi, Sunto-gun, Shizuoka 411-8777 (Japan)

2015-05-15

Highlights: • We clinicopathologically reviewed 22 cases of early mucinous adenocarcinoma. • Radiologically, all cases showed solid or part-solid nodules. • Lobular-bounded margins were observed in 7 cases. • The radiological features could be histologically attributed to mucin production. • One-third of the cases were preoperatively misdiagnosed as inflammatory nodules. - Abstract: Background: The pathological criteria of early-stage mucinous adenocarcinoma of the lung have recently been defined; however, its characteristic radiologic imaging findings are still poorly understood. Thus, this study aimed to clarify the radiologic and pathological findings of early-stage mucinous adenocarcinoma. Materials and methods: In this study, we clinicopathologically reviewed 22 cases of surgically resected mucinous adenocarcinoma in situ (AIS) and minimal invasive adenocarcinoma (MIA), and attempted to elucidate the characteristic radiologic features of early mucinous adenocarcinomas using high-resolution computed tomography (HRCT). Results: Radiologically, the mean value of the maximum diameter of 22 tumours was 2.1 cm (range, 1.0–2.9 cm). Based on the HRCT findings, the tumours were divided into part-solid ground glass nodules (n = 11) and solid nodules (n = 11). The mean CT attenuation value was 25.7 HU (range, 17–35 HU). All tumours, except 3 tumours pathologically diagnosed as AIS, showed air-containing features. According to the preoperative CT findings, 7 (35%) cases were diagnosed as inflammatory nodules. Of these, 4 cases had lobular-bounded margins, and 3 showed vaguely outlined ground glass shadows. Conclusion: The characteristic HRCT findings of mucinous AIS and MIA were solid or part-solid nodules with air-containing spaces. However, some AIS and MIA nodules showed lobular-bounded margins or marginally vaguely outlined ground glass shadows, and were difficult to differentiate from inflammatory nodules.

High-resolution computed tomography findings of early mucinous adenocarcinomas and their pathologic characteristics in 22 surgically resected cases

International Nuclear Information System (INIS)

Miyata, Naoko; Endo, Masahiro; Nakajima, Takashi; Kojima, Hideaki; Maniwa, Tomohiro; Takahashi, Shoji; Isaka, Mitsuhiro; Kameya, Toru; Ohde, Yasuhisa

2015-01-01

Highlights: • We clinicopathologically reviewed 22 cases of early mucinous adenocarcinoma. • Radiologically, all cases showed solid or part-solid nodules. • Lobular-bounded margins were observed in 7 cases. • The radiological features could be histologically attributed to mucin production. • One-third of the cases were preoperatively misdiagnosed as inflammatory nodules. - Abstract: Background: The pathological criteria of early-stage mucinous adenocarcinoma of the lung have recently been defined; however, its characteristic radiologic imaging findings are still poorly understood. Thus, this study aimed to clarify the radiologic and pathological findings of early-stage mucinous adenocarcinoma. Materials and methods: In this study, we clinicopathologically reviewed 22 cases of surgically resected mucinous adenocarcinoma in situ (AIS) and minimal invasive adenocarcinoma (MIA), and attempted to elucidate the characteristic radiologic features of early mucinous adenocarcinomas using high-resolution computed tomography (HRCT). Results: Radiologically, the mean value of the maximum diameter of 22 tumours was 2.1 cm (range, 1.0–2.9 cm). Based on the HRCT findings, the tumours were divided into part-solid ground glass nodules (n = 11) and solid nodules (n = 11). The mean CT attenuation value was 25.7 HU (range, 17–35 HU). All tumours, except 3 tumours pathologically diagnosed as AIS, showed air-containing features. According to the preoperative CT findings, 7 (35%) cases were diagnosed as inflammatory nodules. Of these, 4 cases had lobular-bounded margins, and 3 showed vaguely outlined ground glass shadows. Conclusion: The characteristic HRCT findings of mucinous AIS and MIA were solid or part-solid nodules with air-containing spaces. However, some AIS and MIA nodules showed lobular-bounded margins or marginally vaguely outlined ground glass shadows, and were difficult to differentiate from inflammatory nodules

X-ray-induced acoustic computed tomography of concrete infrastructure

Science.gov (United States)

Tang, Shanshan; Ramseyer, Chris; Samant, Pratik; Xiang, Liangzhong

2018-02-01

X-ray-induced Acoustic Computed Tomography (XACT) takes advantage of both X-ray absorption contrast and high ultrasonic resolution in a single imaging modality by making use of the thermoacoustic effect. In XACT, X-ray absorption by defects and other structures in concrete create thermally induced pressure jumps that launch ultrasonic waves, which are then received by acoustic detectors to form images. In this research, XACT imaging was used to non-destructively test and identify defects in concrete. For concrete structures, we conclude that XACT imaging allows multiscale imaging at depths ranging from centimeters to meters, with spatial resolutions from sub-millimeter to centimeters. XACT imaging also holds promise for single-side testing of concrete infrastructure and provides an optimal solution for nondestructive inspection of existing bridges, pavement, nuclear power plants, and other concrete infrastructure.

Computed tomography scanner applied to soil compaction studies

International Nuclear Information System (INIS)

Vaz, C.M.P.

1989-11-01

The soil compaction problem was studied using a first generation computed tomography scanner (CT). This apparatus gets images of soil cross sections samples, with resolution of a few millimeters. We performed the following laboratory and field experiments: basic experiments of equipment calibrations and resolutions studies; measurements of compacted soil thin layers; measurements of soil compaction caused by agricultural tools; stress-strain modelling in confined soil sample, with several moisture degree; characterizations of soil bulk density profile with samples collected in a hole (trench), comparing with a cone penetrometer technique. (author)

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

High-resolution ex vivo imaging of coronary artery stents using 64-slice computed tomography - initial experience

International Nuclear Information System (INIS)

Rist, Carsten; Nikolaou, Konstantin; Wintersperger, Bernd J.; Reiser, Maximilian F.; Becker, Christoph R.; Flohr, Thomas

2006-01-01

The aim of the study was to evaluate the potential of new-generation multi-slice computed tomography (CT) scanner technology for the delineation of coronary artery stents in an ex vivo setting. Nine stents of various diameters (seven stents 3 mm, two stents 2.5 mm) were implanted into the coronary arteries of ex vivo porcine hearts and filled with a mixture of an iodine-containing contrast agent. Specimens were scanned with a 16-slice CT (16SCT) machine; (Somatom Sensation 16, Siemens Medical Solutions), slice thickness 0.75 mm, and a 64-slice CT (64SCT, Somatom Sensation 64), slice-thickness 0.6 mm. Stent diameters as well as contrast densities were measured, on both the 16SCT and 64SCT images. No significant differences of CT densities were observed between the 16SCT and 64SCT images outside the stent lumen: 265±25HU and 254±16HU (P=0.33), respectively. CT densities derived from the 64SCT images and 16SCT images within the stent lumen were 367±36HU versus 402±28HU, P<0.05, respectively. Inner and outer stent diameters as measured from 16SCT and 64SCT images were 2.68±0.08 mm versus 2.81±0.07 mm and 3.29±0.06 mm versus 3.18±0.07 mm (P<0.05), respectively. The new 64SCT scanner proved to be superior in the ex vivo assessment of coronary artery stents to the conventional 16SCT machine. Increased spatial resolution allows for improved assessment of the coronary artery stent lumen. (orig.)

Computed tomography versus invasive coronary angiography

DEFF Research Database (Denmark)

Napp, Adriane E.; Haase, Robert; Laule, Michael

2017-01-01

Objectives: More than 3.5 million invasive coronary angiographies (ICA) are performed in Europe annually. Approximately 2 million of these invasive procedures might be reduced by noninvasive tests because no coronary intervention is performed. Computed tomography (CT) is the most accurate...... angiography (ICA) is the reference standard for detection of CAD.• Noninvasive computed tomography angiography excludes CAD with high sensitivity.• CT may effectively reduce the approximately 2 million negative ICAs in Europe.• DISCHARGE addresses this hypothesis in patients with low-to-intermediate pretest...

Positron computed tomography. Present and future design alternatives

International Nuclear Information System (INIS)

Phelps, M.E.; Hoffman, E.J.; Sung-Cheng Huang; Kuhl, D.E.

1981-01-01

There are six commercial companies in the United States of America, Canada, Europe and Asia that have or are developing PCT programs. Although positron computed tomography (PCT) system designs are still evolving and all the complex issues of system optimization are still not completely defined, some design concepts have achieved general acceptance. Circumferential designs employing hexagonal, octagonal or circular geometries are preferred since they maximize the tomographic plane efficiency. Bismuth germanate has become the detector of choice because of its high efficiency (intrinsic photopeak and geometric through high packing densities) when the small detectors required for high spatial resolution are used. Caesium fluoride detectors are also being investigated because of their short coincidence time resolution and potential for time of flight measurements. Multiplane systems, consisting of stacked single plane geometries, have been developed to provide higher overall organ efficiency, with some compromise in image quality compared with a single plane system. The most poorly characterized aspect of multiplane systems is the slit and septa shielding design that has a large impact on random and scatter coincidences, count-rate capability, efficiency and uniformity of spatial resolution. Present PCT systems have spatial resolutions in the tomographic plane of about 8 to 17 mm and axial resolution of about 12 to 18 mm. PCT systems that have been or are now being developed are providing the means to demonstrate the unique capability of PCT to provide quantitative measurements of local biochemical and functional processes in man

High-resolution photoacoustic tomography of resting-state functional connectivity in the mouse brain

Science.gov (United States)

Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Quentin; Culver, Joseph P.; Wang, Lihong V.

2014-01-01

The increasing use of mouse models for human brain disease studies presents an emerging need for a new functional imaging modality. Using optical excitation and acoustic detection, we developed a functional connectivity photoacoustic tomography system, which allows noninvasive imaging of resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight functional regions, including the olfactory bulb, limbic, parietal, somatosensory, retrosplenial, visual, motor, and temporal regions, as well as in several subregions. The borders and locations of these regions agreed well with the Paxinos mouse brain atlas. By subjecting the mouse to alternating hyperoxic and hypoxic conditions, strong and weak functional connectivities were observed, respectively. In addition to connectivity images, vascular images were simultaneously acquired. These studies show that functional connectivity photoacoustic tomography is a promising, noninvasive technique for functional imaging of the mouse brain. PMID:24367107

Image reconstruction with shift-variant filtration and its implication for noise and resolution properties in fan-beam computed tomography

International Nuclear Information System (INIS)

Pan Xiaochuan; Yu Lifeng

2003-01-01

In computed tomography (CT), the fan-beam filtered backprojection (FFBP) algorithm is used widely for image reconstruction. It is known that the FFBP algorithm can significantly amplify data noise and aliasing artifacts in situations where the focal lengths are comparable to or smaller than the size of the field of measurement (FOM). In this work, we propose an algorithm that is less susceptible to data noise, aliasing, and other data inconsistencies than is the FFBP algorithm while retaining the favorable resolution properties of the FFBP algorithm. In an attempt to evaluate the noise properties in reconstructed images, we derive analytic expressions for image variances obtained by use of the FFBP algorithm and the proposed algorithm. Computer simulation studies are conducted for quantitative evaluation of the spatial resolution and noise properties of images reconstructed by use of the algorithms. Numerical results of these studies confirm the favorable spatial resolution and noise properties of the proposed algorithm and verify the validity of the theoretically predicted image variances. The proposed algorithm and the derived analytic expressions for image variances can have practical implications for both estimation and detection/classification tasks making use of CT images, and they can readily be generalized to other fan-beam geometries

Application of protons to computer tomography

International Nuclear Information System (INIS)

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

1977-01-01

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

Gas scintillation glass GEM detector for high-resolution X-ray imaging and CT

Energy Technology Data Exchange (ETDEWEB)

Fujiwara, T., E-mail: fujiwara-t@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Mitsuya, Y. [Nuclear Professional School, The University of Tokyo, Tokai, Naka, Ibaraki 319-1188 (Japan); Fushie, T. [Radiment Lab. Inc., Setagaya, Tokyo 156-0044 (Japan); Murata, K.; Kawamura, A.; Koishikawa, A. [XIT Co., Naruse, Machida, Tokyo 194-0045 (Japan); Toyokawa, H. [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Takahashi, H. [Institute of Engineering Innovation, School of Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8654 (Japan)

2017-04-01

A high-spatial-resolution X-ray-imaging gaseous detector has been developed with a single high-gas-gain glass gas electron multiplier (G-GEM), scintillation gas, and optical camera. High-resolution X-ray imaging of soft elements is performed with a spatial resolution of 281 µm rms and an effective area of 100×100 mm. In addition, high-resolution X-ray 3D computed tomography (CT) is successfully demonstrated with the gaseous detector. It shows high sensitivity to low-energy X-rays, which results in high-contrast radiographs of objects containing elements with low atomic numbers. In addition, the high yield of scintillation light enables fast X-ray imaging, which is an advantage for constructing CT images with low-energy X-rays.

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

Science.gov (United States)

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

2002-12-01

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

Computational high-resolution heart phantoms for medical imaging and dosimetry simulations

Energy Technology Data Exchange (ETDEWEB)

Gu Songxiang; Kyprianou, Iacovos [Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD (United States); Gupta, Rajiv, E-mail: songxiang.gu@fda.hhs.gov, E-mail: rgupta1@partners.org, E-mail: iacovos.kyprianou@fda.hhs.gov [Massachusetts General Hospital, Boston, MA (United States)

2011-09-21

Cardiovascular disease in general and coronary artery disease (CAD) in particular, are the leading cause of death worldwide. They are principally diagnosed using either invasive percutaneous transluminal coronary angiograms or non-invasive computed tomography angiograms (CTA). Minimally invasive therapies for CAD such as angioplasty and stenting are rendered under fluoroscopic guidance. Both invasive and non-invasive imaging modalities employ ionizing radiation and there is concern for deterministic and stochastic effects of radiation. Accurate simulation to optimize image quality with minimal radiation dose requires detailed, gender-specific anthropomorphic phantoms with anatomically correct heart and associated vasculature. Such phantoms are currently unavailable. This paper describes an open source heart phantom development platform based on a graphical user interface. Using this platform, we have developed seven high-resolution cardiac/coronary artery phantoms for imaging and dosimetry from seven high-quality CTA datasets. To extract a phantom from a coronary CTA, the relationship between the intensity distribution of the myocardium, the ventricles and the coronary arteries is identified via histogram analysis of the CTA images. By further refining the segmentation using anatomy-specific criteria such as vesselness, connectivity criteria required by the coronary tree and image operations such as active contours, we are able to capture excellent detail within our phantoms. For example, in one of the female heart phantoms, as many as 100 coronary artery branches could be identified. Triangular meshes are fitted to segmented high-resolution CTA data. We have also developed a visualization tool for adding stenotic lesions to the coronaries. The male and female heart phantoms generated so far have been cross-registered and entered in the mesh-based Virtual Family of phantoms with matched age/gender information. Any phantom in this family, along with user

Computational high-resolution heart phantoms for medical imaging and dosimetry simulations

International Nuclear Information System (INIS)

Gu Songxiang; Kyprianou, Iacovos; Gupta, Rajiv

2011-01-01

Cardiovascular disease in general and coronary artery disease (CAD) in particular, are the leading cause of death worldwide. They are principally diagnosed using either invasive percutaneous transluminal coronary angiograms or non-invasive computed tomography angiograms (CTA). Minimally invasive therapies for CAD such as angioplasty and stenting are rendered under fluoroscopic guidance. Both invasive and non-invasive imaging modalities employ ionizing radiation and there is concern for deterministic and stochastic effects of radiation. Accurate simulation to optimize image quality with minimal radiation dose requires detailed, gender-specific anthropomorphic phantoms with anatomically correct heart and associated vasculature. Such phantoms are currently unavailable. This paper describes an open source heart phantom development platform based on a graphical user interface. Using this platform, we have developed seven high-resolution cardiac/coronary artery phantoms for imaging and dosimetry from seven high-quality CTA datasets. To extract a phantom from a coronary CTA, the relationship between the intensity distribution of the myocardium, the ventricles and the coronary arteries is identified via histogram analysis of the CTA images. By further refining the segmentation using anatomy-specific criteria such as vesselness, connectivity criteria required by the coronary tree and image operations such as active contours, we are able to capture excellent detail within our phantoms. For example, in one of the female heart phantoms, as many as 100 coronary artery branches could be identified. Triangular meshes are fitted to segmented high-resolution CTA data. We have also developed a visualization tool for adding stenotic lesions to the coronaries. The male and female heart phantoms generated so far have been cross-registered and entered in the mesh-based Virtual Family of phantoms with matched age/gender information. Any phantom in this family, along with user

Imaging of dopamine transporters in rats using high-resolution pinhole single-photon emission tomography

Energy Technology Data Exchange (ETDEWEB)

Booij, Jan; Bruin, Kora de; Habraken, Jan B.A. [Department of Nuclear Medicine, F2N, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam (Netherlands); Voorn, Pieter [Department of Anatomy, Vrije Universiteit Medical Center, Amsterdam (Netherlands)

2002-09-01

To date, the vast majority of investigations on the dopaminergic system in small animals have been in vitro studies. In comparison with in vitro studies, single-photon emission tomography (SPET) or positron emission tomography (PET) imaging of the dopaminergic system in small animals has the advantage of permitting repeated studies within the same group of animals. Dopamine transporter imaging is a valuable non-invasive tool with which to investigate the integrity of dopaminergic neurons. The purpose of this study was to investigate the feasibility of assessing dopamine transporter density semi-quantitatively in rats using a recently developed high-resolution pinhole SPET system. This system was built exclusively for imaging of small animals. In this unique single-pinhole system, the animal rotates instead of the collimated detector. The system has proven to have a high spatial resolution. We performed SPET imaging with [{sup 123}I]FP-CIT to quantify striatal dopamine transporters in rat brain. In all seven studied control rats, symmetrical striatal binding to dopamine transporters was seen 2 h after injection of the radiotracer, with striatal-to-cerebellar binding ratios of approximately 3.5. In addition, test/retest variability of the striatal-to-cerebellar binding ratios was studied and found to be 14.5%. Finally, in unilaterally 6-hydroxydopamine-lesioned rats, striatal binding was only visible on the non-lesioned side. Quantitative analysis revealed that striatal-to-cerebellar SPET ratios were significantly lower on the lesioned (mean binding ratio 2.2{+-}0.2) than on the non-lesioned (mean ratio 3.1{+-}0.4) side. The preliminary results of this study indicate that semi-quantitative assessment of striatal dopamine transporter density using our recently developed high-resolution single-pinhole SPET system is feasible in living rat brain. (orig.)

Characteristics and applications of a flat panel computer tomography system

International Nuclear Information System (INIS)

Knollmann, F.; Valencia, R.; Obenauer, S.; Buhk, J.H.

2006-01-01

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

A comparison of methods for demonstrating artificial bone lesions; conventional versus computer tomography

International Nuclear Information System (INIS)

Heller, M.; Wenk, M.; Jend, H.H.

1984-01-01

Conventional tomography (T) and computer tomography (CT) were used for examining 97 artificial bone lesions at various sites. The purpose of the study was to determine how far CT can replace T in the diagnosis of skeletal abnormalities. The results have shown that modern CT, particularly in its high resolution form, equals T and provides additional information (substrate of a lesion, its relationship to neighbouring tissues, simultaneous demonstration of soft tissue etc.). These cannot be shown successfully by T. It follows that CT is indicated as the primary method of examination for lesions of the facial skeleton, skull base, spine, pelvis and, to some extent, extremities. (orig.) [de

Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation; Opacidades em vidro fosco nas doencas pulmonares difusas: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

Energy Technology Data Exchange (ETDEWEB)

Santos, Maria Lucia de Oliveira; Vianna, Alberto Domingues; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Disciplina de Radiologia; Moraes, Heleno Pinto de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Patologia]. E-mail: edmarchiori@zipmail.com.br

2003-12-01

Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its un specificity, association with other radiological, clinical and pathological findings must be considered for an accurate diagnostic interpretation. In this paper were reviewed 62 computed tomography examinations of patients with diffuse pulmonary diseases of 14 different etiologies in which ground-glass opacity was the only or the most remarkable finding, and correlated this findings with pathology abnormalities seen on specimens obtained from biopsies or necropsies. In pneumocystosis, ground-glass opacities correlated histologically with alveolar occupation by a foaming material containing parasites, in bronchiole alveolar cell carcinoma with thickening of the alveolar septa and occupation of the lumen by mucus and tumoral cells, in paracoccidioidomycosis with thickening of the alveolar septa, areas of fibrosis and alveolar bronchopneumonia exudate, in sarcoidosis with fibrosis or clustering of granulomas and in idiopathic pulmonary fibrosis with alveolar septa thickening due to fibrosis. Alveolar occupation by blood was found in cases of leptospirosis, idiopathic hemo siderosis, metastatic kidney tumor and invasive aspergillosis whereas oily vacuole were seen in lipoid pneumonia, proteinaceous and lipo proteinaceous material in silico proteinosis and pulmonary alveolar proteinosis, and edematous fluid in cardiac failure. (author)

Prospects of linear reconstruction in atomic resolution electron holographic tomography

International Nuclear Information System (INIS)

Krehl, Jonas; Lubk, Axel

2015-01-01

Tomography commonly requires a linear relation between the measured signal and the underlying specimen property; for Electron Holographic Tomography this is given by the Phase Grating Approximation (PGA). While largely valid at medium resolution, discrepancies arise at high resolution imaging conditions. We set out to investigate the artefacts that are produced if the reconstruction still assumes the PGA even with an atomic resolution tilt series. To forego experimental difficulties the holographic tilt series was simulated. The reconstructed electric potential clearly shows peaks at the positions of the atoms. These peaks have characterisitic deformations, which can be traced back to the defocus a particular atom has in the holograms of the tilt series. Exchanging an atom for one of a different atomic number results in a significant change in the reconstructed potential that is well contained within the atom's peak. - Highlights: • We simulate a holographic tilt series of a nanocrystal with atomic resolution. • Using PGA-based Holographic Tomography we reconstruct the atomic structure. • The reconstruction shows characteristic artefacts, chiefly caused by defocus. • Changing one atom's Z produces a well localised in the reconstruction

Prospects of linear reconstruction in atomic resolution electron holographic tomography

Energy Technology Data Exchange (ETDEWEB)

Krehl, Jonas, E-mail: Jonas.Krehl@triebenberg.de; Lubk, Axel

2015-03-15

Tomography commonly requires a linear relation between the measured signal and the underlying specimen property; for Electron Holographic Tomography this is given by the Phase Grating Approximation (PGA). While largely valid at medium resolution, discrepancies arise at high resolution imaging conditions. We set out to investigate the artefacts that are produced if the reconstruction still assumes the PGA even with an atomic resolution tilt series. To forego experimental difficulties the holographic tilt series was simulated. The reconstructed electric potential clearly shows peaks at the positions of the atoms. These peaks have characterisitic deformations, which can be traced back to the defocus a particular atom has in the holograms of the tilt series. Exchanging an atom for one of a different atomic number results in a significant change in the reconstructed potential that is well contained within the atom's peak. - Highlights: • We simulate a holographic tilt series of a nanocrystal with atomic resolution. • Using PGA-based Holographic Tomography we reconstruct the atomic structure. • The reconstruction shows characteristic artefacts, chiefly caused by defocus. • Changing one atom's Z produces a well localised in the reconstruction.

Cone-beam micro computed tomography dedicated to the breast.

Science.gov (United States)

Sarno, Antonio; Mettivier, Giovanni; Di Lillo, Francesca; Cesarelli, Mario; Bifulco, Paolo; Russo, Paolo

2016-12-01

We developed a scanner for micro computed tomography dedicated to the breast (BµCT) with a high resolution flat-panel detector and a microfocus X-ray tube. We evaluated the system spatial resolution via the 3D modulation transfer function (MTF). In addition to conventional absorption-based X-ray imaging, such a prototype showed capabilities for propagation-based phase-contrast and related edge enhancement effects in 3D imaging. The system limiting spatial resolution is 6.2mm -1 (MTF at 10%) in the vertical direction and 3.8mm -1 in the radial direction, values which compare favorably with the spatial resolution reached by mini focus breast CT scanners of other groups. The BµCT scanner was able to detect both microcalcification clusters and masses in an anthropomorphic breast phantom at a dose comparable to that of two-view mammography. The use of a breast holder is proposed in order to have 1-2min long scan times without breast motion artifacts. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

High-contrast differentiation resolution 3D imaging of rodent brain by X-ray computed microtomography

Science.gov (United States)

Zikmund, T.; Novotná, M.; Kavková, M.; Tesařová, M.; Kaucká, M.; Szarowská, B.; Adameyko, I.; Hrubá, E.; Buchtová, M.; Dražanová, E.; Starčuk, Z.; Kaiser, J.

2018-02-01

The biomedically focused brain research is largely performed on laboratory mice considering a high homology between the human and mouse genomes. A brain has an intricate and highly complex geometrical structure that is hard to display and analyse using only 2D methods. Applying some fast and efficient methods of brain visualization in 3D will be crucial for the neurobiology in the future. A post-mortem analysis of experimental animals' brains usually involves techniques such as magnetic resonance and computed tomography. These techniques are employed to visualize abnormalities in the brains' morphology or reparation processes. The X-ray computed microtomography (micro CT) plays an important role in the 3D imaging of internal structures of a large variety of soft and hard tissues. This non-destructive technique is applied in biological studies because the lab-based CT devices enable to obtain a several-micrometer resolution. However, this technique is always used along with some visualization methods, which are based on the tissue staining and thus differentiate soft tissues in biological samples. Here, a modified chemical contrasting protocol of tissues for a micro CT usage is introduced as the best tool for ex vivo 3D imaging of a post-mortem mouse brain. This way, the micro CT provides a high spatial resolution of the brain microscopic anatomy together with a high tissue differentiation contrast enabling to identify more anatomical details in the brain. As the micro CT allows a consequent reconstruction of the brain structures into a coherent 3D model, some small morphological changes can be given into context of their mutual spatial relationships.

Exogenous lipoid pneumonia: high-resolution CT findings

International Nuclear Information System (INIS)

Lee, J.S.; Song, K.S.; Lim, T.H.; Im, J.G.; Seo, J.B.

1999-01-01

The aim of this study was to assess high-resolution computed tomography (HRCT) findings of exogenous lipoid pneumonia. High-resolution computed tomography was obtained in 25 patients with proven exogenous lipoid pneumonia resulting from aspiration of squalene (derived from shark liver oil). Diagnosis was based on biopsy (n = 9), bronchoalveolar lavage (n = 8), or sputum cytology and clinical findings (n = 8). The clinical history of taking squalene was confirmed in all patients. The CT findings were classified into three patterns: diffuse ground-glass opacity, consolidation, and interstitial abnormalities. Distribution of the abnormalities, duration of taking squalene, predisposing factors for aspiration, and route of administration were analyzed. Ten patients showed diffuse ground-glass opacity pattern. Seven of 10 patients had predisposing conditions such as unconsciousness, pharyngeal dysmotility, or motor disturbances, and 6 patients had a recent history of taking large amount of squalene through nasal route. Seven patients who had consolidation pattern had a history of taking squalene for several months and did not have any predisposing factor. All of the 5 patients who had a pattern of interstitial abnormalities had a history of taking squalene longer than 1 year and showed segmental distribution of interstitial thickening with interposing ground-glass opacities. Three patients simultaneously had two different patterns at different lobes of the lung. The HRCT findings of lipoid pneumonia are ground-glass opacities, consolidation, and interstitial abnormalities. These HRCT findings with appropriate inquiries could be useful for diagnosis of exogeneous lipoid pneumonia. (orig.)

Inside marginal adaptation of crowns by X-ray micro-computed tomography

International Nuclear Information System (INIS)

Dos Santos, T. M.; Lima, I.; Lopes, R. T.; Author, S. B. Jr.

2015-01-01

The objective of this work was to access dental arcade by using X-ray micro-computed tomography. For this purpose high resolution system was used and three groups were studied: Zirkonzahn CAD-CAM system, IPS e.max Press, and metal ceramic. The three systems assessed in this study showed results of marginal and discrepancy gaps clinically accepted. The great result of 2D and 3D evaluations showed that the used technique is a powerful method to investigate quantitative characteristics of dental arcade. (authors)

Inside marginal adaptation of crowns by X-ray micro-computed tomography

Energy Technology Data Exchange (ETDEWEB)

Dos Santos, T. M.; Lima, I.; Lopes, R. T. [Nuclear Instrumentation Laboratory, Nuclear Engineering Program, Federal University of Rio de Janeiro, RJ, (Brazil); Author, S. B. Jr. [Department of Physics, Colorado State University, Ft. Collins, CO 80523, (United States)

2015-07-01

The objective of this work was to access dental arcade by using X-ray micro-computed tomography. For this purpose high resolution system was used and three groups were studied: Zirkonzahn CAD-CAM system, IPS e.max Press, and metal ceramic. The three systems assessed in this study showed results of marginal and discrepancy gaps clinically accepted. The great result of 2D and 3D evaluations showed that the used technique is a powerful method to investigate quantitative characteristics of dental arcade. (authors)

Experience with computed transmission tomography of the heart in vivo

International Nuclear Information System (INIS)

Carlsson, E.; Lipton, M.J.; Skioeldebrand, C.G.; Berninger, W.H.; Redington, R.W.

1980-01-01

Cardiac computed tomography in its present form provides useful information about the heart for clinical use in patients with heart disease and for investigative work in such patients and living animals. Its great reconstructive power and unmatched density resolution are particularly advantageous in the study of ischemic heart disease. Because of its non-invasive character cardiac computed tomography has the potential of becoming an effective screening tool for large numbers of patients with suspected or known coronary heart desiase. Other cardiac conditions such as valve disease and congenital lesions can also be examined with high diagnostic yield. However presently available scanners suffer from low repetion rate, long scan times and the fact that only one transverse cardiac level at a time can be obtained. The development which must be accomplished in order to eliminate these weaknesses is technically feasible. The availability of a dynamic cardiac scanner would greatly benefit the treatment of patients with heart disease and facilitate the inquiry into the pathophysiology of such diseases. (orig.) [de

Impulse-response analysis of planar computed tomography for nondestructive test

Energy Technology Data Exchange (ETDEWEB)

Kim, Dae Cheon; Kim, Seung Ho; Kim, Ho Kyung [KAERI, Daejeon (Korea, Republic of)

2016-05-15

There have been reported that the use of radiation imaging such as digital radiography, computed tomography (CT), and digital tomosynthesis (DTS) for the nondestructive test (NDT) widely is spreading. These methods have merits and demerits of their own, in terms of image quality and inspection speed. Therefore, image for these methods for NDT should have acceptable image quality and high speed. In this study, we quantitatively evaluate impulse responses of reconstructed images from the filtered backprojection (FBP), which are most widely used in planar computed tomography (pCT) systems. We first evaluate image performance metrics due to the contrast, depth resolution, and then we design the figure of merit including image performance and system parameters, such as tube load and reconstruction speed. The final goal of this study is the application of these methods to the nondestructive test. In order to accomplish it, further study is needed. First of all, the results of the ASF from various numbers of views. Second, the analysis of modulation transfer function, noise power spectrum, and detective quantum efficiency from various angular range and numbers of views.

Computer stress study of bone with computed tomography

International Nuclear Information System (INIS)

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

1986-01-01

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

Three dimensional characterization of laser ablation craters using high resolution X-ray computed tomography

Science.gov (United States)

Galmed, A. H.; du Plessis, A.; le Roux, S. G.; Hartnick, E.; Von Bergmann, H.; Maaza, M.

2018-01-01

Laboratory X-ray computed tomography is an emerging technology for the 3D characterization and dimensional analysis of many types of materials. In this work we demonstrate the usefulness of this characterization method for the full three dimensional analysis of laser ablation craters, in the context of a laser induced breakdown spectroscopy setup. Laser induced breakdown spectroscopy relies on laser ablation for sampling the material of interest. We demonstrate here qualitatively (in images) and quantitatively (in terms of crater cone angles, depths, diameters and volume) laser ablation crater analysis in 3D for metal (aluminum) and rock (false gold ore). We show the effect of a Gaussian beam profile on the resulting crater geometry, as well as the first visual evidence of undercutting in the rock sample, most likely due to ejection of relatively large grains. The method holds promise for optimization of laser ablation setups especially for laser induced breakdown spectroscopy.

Comparison of chest radiography and high-resolution computed tomography findings in early and low-grade coal worker's pneumoconiosis

Energy Technology Data Exchange (ETDEWEB)

Savranlar, A.; Altin, R.; Mahmutyazicioglu, K.; Ozdemir, H.; Kart, L.; Ozer, T.; Gundogdu, S. [Zonguldak Karaelmas University, Zonguldak (Turkey). Faculty of Medicine

2004-08-01

High-resolution computed tomography (HRCT) is more sensitive than chest X-ray (CXR) in the depiction of parenchymal abnormalities. The paper presents and compares CXR and HRCT findings in coal workers with and without early and low-grade coal worker's pneumoconiosis (CWP). 71 coal workers were enrolled in the study. HRCT's were graded according to Hosoda and Shida's Japanese classification. After grading, 67 workers with CXR profusion 0/0-2/2 were included in the study. Four patients with major opacity were excluded. Profusion 0/1 to 1/1 cases were accepted as early and profusion and 2/2 cases as low-grade pneumoconiosis. Discordance rate was found to be higher in the early pneumoconiosis cases with negative CXR than low-grade pneumoconiosis (60, 36 and 8%, respectively). When coal miners with normal CXR were evaluated by HRCT, six out of 10 cases were diagnosed as positive. In low-grade pneumoconiosis group, the number of patients with positive CXR but negative HRCT were low in comparison to patients with CXR negative and early pneumoconiosis findings. Most of the CXR category 0 patients (10/16) were diagnosed as category 1 by HRCT. Eleven cases diagnosed as CXR category 1 were diagnosed as category 0 (7/11) and category 2 (4/11) by HRCT. In CXR category 2 (eight cases), there were four cases diagnosed as category 1 by HRCT. Overall, discordance between CXR and HRCT was high, especially for CXR negative and early pneumoconiosis cases. The role of CXR in screening coal workers to detect early pneumoconiosis findings should be questioned. The authors suggest using HRCT as a standard screening method instead of CXR to distinguish between normal and early pneumoconiosis.

Submicron Resolution Spectral-Domain Optical Coherence Tomography

KAUST Repository

Alarousu, Erkki; Jabbour, Ghassan

2013-01-01

Apparatuses and systems for submicron resolution spectral-domain optical coherence tomography (OCT) are disclosed. The system may use white light sources having wavelengths within 400-1000 nanometers, and achieve resolution below 1 .mu

Use of a YAP:Ce matrix coupled to a position-sensitive photomultiplier for high resolution positron emission tomography

International Nuclear Information System (INIS)

Del Guerra, A.; Zavattini, G.; Notaristefani, F. de; Giganti, M.; Piffanelli, A.; Pani, R.; Turra, A.

1996-01-01

A new scintillation detector system has been designed for application in high resolution Positron Emission Tomography (PET). The detector is a bundle of small YAlO 3 :Ce (YAP) crystals closely packed (0.2 x 0.2 x 3.0 cm 3 ), coupled to a position sensitive photomultiplier tube (PSPMT). The preliminary results obtained for spatial resolution, time resolution, energy resolution and efficiency of two such detectors working in coincidence are presented. These are 1.2 mm for the FWHM spatial resolution, 2.0 ns for the FWHM time resolution and 20% for the FWHM energy resolution at 511 keV. The measured efficiency is (44 ± 3)% with a 150 keV threshold and (20 ± 2)% with a 300 keV threshold

Fundamentals of cone beam computed tomography for a prosthodontist

Directory of Open Access Journals (Sweden)

George Puthenpurayil John

2015-01-01

Full Text Available Cone beam computed tomography (CBCT, also referred to as C-arm computed tomography [CT], cone beam volume CT, or flat panel CT is a medical imaging technique of X-ray CT where the X-rays are divergent, forming a cone. [1] CBCT systems have been designed for imaging hard tissues of the maxillofacial region. CBCT is capable of providing sub-millimeter resolution in images of high diagnostic quality, with short scanning times (10-70 s and radiation dosages reportedly up to 15-100 times lower than those of conventional CT scans. Increasing availability of this technology provides the dental clinician with an imaging modality capable of providing a three-dimensional representation of the maxillofacial skeleton with minimal distortion. The aim of this article is to sensitize the Prosthodontist to CBCT technology, provide an overview of currently available maxillofacial CBCT systems and review the specific application of various CBCT display modes to clinical Prosthodontic practice. A MEDLINE search for relevant articles in this specific area of interest was conducted. The selected articles were critically reviewed and the data acquired were systematically compiled.

Wrist ligament injuries: value of post-arthrography computed tomography

Energy Technology Data Exchange (ETDEWEB)

Theumann, N.; Schnyder, P.; Meuli, R. [Dept. of Diagnostic and Interventional Radiology, University Hospital, CHUV, Lausanne (Switzerland); Favarger, N. [Clinique Longeraie, Lausanne (Switzerland)

2001-02-01

Objective: To evaluate the use of post-arthrography high-resolution computed tomography in wrist ligament injuries.Design and patients: Thirty-six consecutive patients who had a history and clinical findings suggestive of ligamentous injuries of the wrist were prospectively studied. The findings of three-compartment arthrography and post-arthrography computed tomography (arthro-CT) were compared with those of arthroscopy. The evaluation concentrates on the detection and precise localization of ligament lesions in the triangular fibrocartilage (TFC), the scapholunate ligament (SLL) and the lunotriquetral ligament (LTL).Results: For TFC, SLL and LTL lesions, standard arthrography responded with a sensitivity and specificity of 85% and 100%, 85% and 100%, 80% and 100% respectively, while arthro-CT showed a sensitivity and specificity of 85% and 100%, 100% and 100%, 80% and 100% respectively. The precise localization of the lesions was possible only with arthro-CT.Conclusion: The sensitivity and specificity of standard arthrography and arthro-CT are similar, although the latter shows the site of tears or perforation with greater precision, while conventional arthrography demonstrates them indirectly. This precision is essential and may have clinical implications for the success of treatment procedures. (orig.)

Fundamentals of cone beam computed tomography for a prosthodontist

Science.gov (United States)

John, George Puthenpurayil; Joy, Tatu Elenjickal; Mathew, Justin; Kumar, Vinod R. B.

2015-01-01

Cone beam computed tomography (CBCT, also referred to as C-arm computed tomography [CT], cone beam volume CT, or flat panel CT) is a medical imaging technique of X-ray CT where the X-rays are divergent, forming a cone.[1] CBCT systems have been designed for imaging hard tissues of the maxillofacial region. CBCT is capable of providing sub-millimeter resolution in images of high diagnostic quality, with short scanning times (10–70 s) and radiation dosages reportedly up to 15–100 times lower than those of conventional CT scans. Increasing availability of this technology provides the dental clinician with an imaging modality capable of providing a three-dimensional representation of the maxillofacial skeleton with minimal distortion. The aim of this article is to sensitize the Prosthodontist to CBCT technology, provide an overview of currently available maxillofacial CBCT systems and review the specific application of various CBCT display modes to clinical Prosthodontic practice. A MEDLINE search for relevant articles in this specific area of interest was conducted. The selected articles were critically reviewed and the data acquired were systematically compiled. PMID:26929479

Italian Chapter of the International Society of Cardiovascular Ultrasound expert consensus document on coronary computed tomography angiography: overview and new insights.

Science.gov (United States)

Sozzi, Fabiola B; Maiello, Maria; Pelliccia, Francesco; Parato, Vito Maurizio; Canetta, Ciro; Savino, Ketty; Lombardi, Federico; Palmiero, Pasquale

2016-09-01

Coronary computed tomography angiography is a noninvasive heart imaging test currently undergoing rapid development and advancement. The high resolution of the three-dimensional pictures of the moving heart and great vessels is performed during a coronary computed tomography to identify coronary artery disease and classify patient risk for atherosclerotic cardiovascular disease. The technique provides useful information about the coronary tree and atherosclerotic plaques beyond simple luminal narrowing and plaque type defined by calcium content. This application will improve image-guided prevention, medical therapy, and coronary interventions. The ability to interpret coronary computed tomography images is of utmost importance as we develop personalized medical care to enable therapeutic interventions stratified on the bases of plaque characteristics. This overview provides available data and expert's recommendations in the utilization of coronary computed tomography findings. We focus on the use of coronary computed tomography to detect coronary artery disease and stratify patients at risk, illustrating the implications of this test on patient management. We describe its diagnostic power in identifying patients at higher risk to develop acute coronary syndrome and its prognostic significance. Finally, we highlight the features of the vulnerable plaques imaged by coronary computed tomography angiography. © 2016, Wiley Periodicals, Inc.

Tuberculous otitis media: findings on high-resolution CT

International Nuclear Information System (INIS)

Lungenschmid, D.; Buchberger, W.; Schoen, G.; Schoepf, R.; Mihatsch, T.; Birbamer, G.; Wicke, K.

1993-01-01

We describe two cases of tuberculous otitis media studied with high-resolution computed tomography (CT). Findings included extensive soft tissue densities with fluid levels in the tympanic cavity, the antrum, the mastoid and petrous air cells. Multifocal bony erosions and reactive bone sclerosis were seen as well. CT proved valuable for planning therapy by accurately displaying the involvement of the various structures of the middle and inner ear. However, the specific nature of the disease could only be presumed. (orig.)

Idiopathic pulmonary fibrosis and collagen vascular diseases - high resolution CT findings

International Nuclear Information System (INIS)

Ferreira Neto, Armando Leao; Mogami, Roberto; Marchiori, Edson; Capone, Domenico

1996-01-01

The aspects of the thorax high-resolution computed tomography of 15 patients with idiopathic pulmonary fibrosis and 11 patients with collagen vascular diseases are described and characterized mainly by the presence of reticular lesions with little cysts predominantly in the periphery and lower lobes. They may be associated with ground-glass lesions that, as usual, means areas of alveolitis. (author)

Development of novel emission tomography system

Science.gov (United States)

Fu, Geng

In recent years, small animals, such as mice and rats, have been widely used as subjects of study in biomedical research while molecular biology and imaging techniques open new opportunities to investigate disease model. With the help of medical imaging techniques, researchers can investigate underlying mechanisms inside the small animal, which are useful for both early diagnosis and treatment monitoring. Based on tracer principle single photon emission computed tomography (SPECT) has increased popularity in small animal imaging due to its higher spatial resolution and variety of single-photon emitting radionuclides. Since the image quality strongly depends on the detector properties, both scintillation and semiconductor detectors are under active investigation for high resolution X-ray and gamma ray photon detection. The desired detector properties include high intrinsic spatial resolution, high energy resolution, and high detection efficiency. In this thesis study, we have made extensive efforts to develop novel emission tomography system, and evaluate the use of both semiconductor and ultra-high resolution scintillation detectors for small animal imaging. This thesis work includes the following three areas. Firstly, we have developed a novel energy-resolved photon counting (ERPC) detector. With the benefits of high energy resolution, high spatial resolution, flexible detection area, and a wide dynamic range of 27--200keV, ERPC detector is well-suited for small animal SPECT applications. For prototype ERPC detector excellent imaging (˜350microm) and spectroscopic performance (4keV Co-57 122keV) has been demonstrated in preliminary study. Secondly, to further improve spatial resolution to hundred-micron level, an ultra-high resolution Intensified EMCCD (I-EMCCD) detector has been designed and evaluated. This detector consists of the newly developed electron multiplying CCD (EMCCD) sensor, columnar CsI(Tl) scintillator, and an electrostatic de-magnifier (DM) tube

Grating-based X-ray Dark-field Computed Tomography of Living Mice.

Science.gov (United States)

Velroyen, A; Yaroshenko, A; Hahn, D; Fehringer, A; Tapfer, A; Müller, M; Noël, P B; Pauwels, B; Sasov, A; Yildirim, A Ö; Eickelberg, O; Hellbach, K; Auweter, S D; Meinel, F G; Reiser, M F; Bech, M; Pfeiffer, F

2015-10-01

Changes in x-ray attenuating tissue caused by lung disorders like emphysema or fibrosis are subtle and thus only resolved by high-resolution computed tomography (CT). The structural reorganization, however, is of strong influence for lung function. Dark-field CT (DFCT), based on small-angle scattering of x-rays, reveals such structural changes even at resolutions coarser than the pulmonary network and thus provides access to their anatomical distribution. In this proof-of-concept study we present x-ray in vivo DFCTs of lungs of a healthy, an emphysematous and a fibrotic mouse. The tomographies show excellent depiction of the distribution of structural - and thus indirectly functional - changes in lung parenchyma, on single-modality slices in dark field as well as on multimodal fusion images. Therefore, we anticipate numerous applications of DFCT in diagnostic lung imaging. We introduce a scatter-based Hounsfield Unit (sHU) scale to facilitate comparability of scans. In this newly defined sHU scale, the pathophysiological changes by emphysema and fibrosis cause a shift towards lower numbers, compared to healthy lung tissue.

Technical note: a landmark-based approach to the study of the ear ossicles using ultra-high-resolution X-ray computed tomography data.

Science.gov (United States)

Schmidt, Jodi L; Cole, Theodore M; Silcox, Mary T

2011-08-01

Previous study of the ear ossicles in Primates has demonstrated that they vary on both functional and phylogenetic bases. Such studies have generally employed two-dimensional linear measurements rather than three-dimensional data. The availability of Ultra- high-resolution X-ray computed tomography (UhrCT) has made it possible to accurately image the ossicles so that broadly accepted methodologies for acquiring and studying morphometric data can be applied. Using UhrCT data also allows for the ossicular chain to be studied in anatomical position, so that it is possible to consider the spatial and size relationships of all three bones. One issue impeding the morphometric study of the ear ossicles is a lack of broadly recognized landmarks. Distinguishing landmarks on the ossicles is difficult in part because there are only two areas of articulation in the ossicular chain, one of which (the malleus/incus articulation) has a complex three-dimensional form. A measurement error study is presented demonstrating that a suite of 16 landmarks can be precisely located on reconstructions of the ossicles from UhrCT data. Estimates of measurement error showed that most landmarks were highly replicable, with an average CV for associated interlandmark distances of less than 3%. The positions of these landmarks are chosen to reflect not only the overall shape of the bones in the chain and their relative positions, but also functional parameters. This study should provide a basis for further examination of the smallest bones in the body in three dimensions. Copyright © 2011 Wiley-Liss, Inc.

PATTERN OF INTERSTITIAL LUNG DISEASE AS SEEN BY HIGH RESOLUTION COMPUTERISED TOMOGRAPHY.

Science.gov (United States)

Onyambu, C K; Waigwa, M N

2012-09-01

Diffuse lung diseases constitute a major cause of morbidity and mortality worldwide. High Resolution Computed Tomography (HRCT) is the recommended imaging technique in the diagnosis, assessment and followup of these diseases. To describe the pattern of HRCT findings in patients with suspected interstitial lung disease. Kenyatta National Hospital (KNH), Nairobi Hospital and MP Shah Hospital; all situated in Nairobi, during the period February to August 2010. One hundred and one patients sent for HRCT in the six month study period. A total of 101 patients were recruited with age range 18 to 100 years, with a mean age of 53.6 (SD 19.7) years and a median age of 54 years. The male-female ratio was 1.2:1. Cough [80.2% (n = 81)] was the most common presenting complaint followed by dyspnoea (53.5%, n = 53) and chest pain [24.8% (n = 25)]. Overall, the predominant pattern of involvement on chest HRCT was reticular pattern seen in 56.1% (n = 82) of patients, followed by honey-comb pattern (37.8%, n = 82). The study demonstrated marked lung parenchymal destruction in most cases; a poor prognostic indicator which could have been due to delayed referral. HRCT has a high pick up rate of subtle parenchymal lung lesions as well as defining the lesions and their distribution compared to plain chest radiography. This is important in narrowing the differential diagnosis as well as for pre-biopsy planning. The diagnosis of ILD requires a multidisciplinary approach including a detailed clinical history, physical findings, and laboratory investigations, radiological and histological assessment.

Children's (Pediatric) CT (Computed Tomography)

Medline Plus

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

Voluminal modelling for the characterization of wastes packages by gamma emission computed tomography

International Nuclear Information System (INIS)

Pettier, J.L.; Thierry, R.

2001-01-01

The aim of this work is to model the measurement process used for multi-photon emission computed tomography on nuclear waste drum. Our model MEPHISTO (Multi-Energy PHoton Imagery through Segmented TOmography) takes into account all phenomena influencing gamma emergent flux and high resolution spectrometric measurements using an HpGe detector through a collimator aperture. These phenomena are absorption and Compton scattering of gamma photons in waste drum, geometrical blur, spatial and energetic response of the detector. The analysis of results shows better localisation and quantification performances compared with a Ray-Driven method. It proves the importance of an accurate modelization of collimated measurements to reduce noise and stabilize iterative image reconstructions. (authors)

Batch Computed Tomography Analysis of Projectiles

Science.gov (United States)

2016-05-01

ARL-TR-7681 ● MAY 2016 US Army Research Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt, Chris M...Laboratory Batch Computed Tomography Analysis of Projectiles by Michael C Golt and Matthew S Bratcher Weapons and Materials Research...values to account for projectile variability in the ballistic evaluation of armor. 15. SUBJECT TERMS computed tomography , CT, BS41, projectiles

Computed tomography with multidetectors in the diagnosis of coronary stenosis

International Nuclear Information System (INIS)

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

2007-01-01

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

Evolution of Computed Tomography Findings in Secondary Aortoenteric Fistula

International Nuclear Information System (INIS)

Bas, Ahmet; Simsek, Osman; Kandemirli, Sedat Giray; Rafiee, Babak; Gulsen, Fatih; Numan, Furuzan

2015-01-01

Aortoenteric fistula is a rare but significant clinical entity associated with high morbidity and mortality if remain untreated. Clinical presentation and imaging findings may be subtle and prompt diagnosis can be difficult. Herein, we present a patient who initially presented with abdominal pain and computed tomography showed an aortic aneurysm compressing duodenum without any air bubbles. One month later, the patient presented with gastrointestinal bleeding and computed tomography revealed air bubbles within aneurysm. With a diagnosis of aortoenteric fistula, endovascular aneurysm repair was carried out. This case uniquely presented the computed tomography findings in progression of an aneurysm to an aortoenteric fistula

Computed tomography evaluation of pulmonary alterations after radiotherapy

International Nuclear Information System (INIS)

Neves, Mauricio de Carvalho; Grossi, Carla Martins De; Santos, Alair Augusto S.M.D. dos; Carvalho, Renato; Santos, Marcia Heizer; Lodi, Nilson Jose; Meirelles, Maria Angelica V.F.O.; Fontes, Cristina Asvolinsque P.; Neves Filho, Henrique Cezar; Fernandes, Marcus Vinicius C.; Ferreira Neto, Armando Leao; Miranda Neto, Darci P.; Rios, Anna Cristina S.; Andreiuolo, Pedro Angelo; Koch, Hilton Augusto

1998-01-01

A retrospective study of 15 patients with primary tumors, 13 of the lung and 2 breast cancers, treated in the Hospital Santa Cruz/Beneficiencia Portuguesa de Niteroi, RJ, in the period comprised from February 1991 to October 1996, was done. The pulmonary radiotherapy effects were observed in two clinical presentations - acute (radiation pneumonitis) and chronic (radiation fibrosis) -, both depending upon the radiotherapy doses, the radiation area, the individual susceptibility and the previous chemotherapy. Signs of pulmonary fibrosis were found in 73.3% of the patients, pneumonitis in 20.0% and absence of changes after radiation in 6.6%. Computed tomography was an excellent noninvasive diagnostic method in demonstrating radiotherapy-induced pulmonary changes, more evident in high-resolution technique scans. (author)

Multislice helical computed tomography in the evaluation of lumbar spine diseases

International Nuclear Information System (INIS)

Rosemberg, Laercio Alberto; Rios, Adriana Martins; Almeida, Milena Oliveira; Garbaccio, Viviane Ladeira; Kim, Nelson Ji Tae; Daniel, Mauro Miguel; Funari, Marcelo Buarque de Gusmao

2003-01-01

Multislice computed tomography has advantages in comparison to conventional computer tomography such as reduction in study time, lower radiation dose, fewer metal artifacts and high quality multiplanar reformatting and three-dimensional reconstructions. We reviewed approximately 300 lumbar spine examinations and selected the most illustrative cases including congenital anomalies, degenerative lesions, spinal infections, neoplasms traumatic injuries, spondylolysis and postoperative changes. In the majority of the cases the high quality multiplanar reformatted and volume reconstructions of multislice computed tomography allowed better evaluation of the lesions, particularly in the cases of complex anatomy (author)

Computed tomography of the normal feline nasal cavity and paranasal sinuses

International Nuclear Information System (INIS)

Losonsky, J.M.; Abbott, L.C.; Kuriashkin, I.V.

1997-01-01

Computed tomography (CT) images of the feline nasal cavity and paranasal sinuses were acquired from normal adult cats, Good resolution and anatomic detail were obtained from the CT images using soft tissue formatting. A description of normal feline nasal cavity and paranasal sinus anatomy using CT is presented

Non-destructive morphological observations of the fleshy brittle star, Asteronyx loveni using micro-computed tomography (Echinodermata, Ophiuroidea, Euryalida).

Science.gov (United States)

Okanishi, Masanori; Fujita, Toshihiko; Maekawa, Yu; Sasaki, Takenori

2017-01-01

The first morphological observation of a euryalid brittle star, Asteronyx loveni , using non-destructive X-ray micro-computed tomography (µCT) was performed. The body of euryalids is covered by thick skin, and it is very difficult to observe the ossicles without dissolving the skin. Computed tomography with micrometer resolution (approximately 4.5-15.4 µm) was used to construct 3D images of skeletal ossicles and soft tissues in the ophiuroid's body. Shape and positional arrangement of taxonomically important ossicles were clearly observed without any damage to the body. Detailed pathways inside the vertebral ossicles, lateral arm plates, and arm spines for passage of nerves and water vascular structures were observed. Inter-vertebral muscles were also observed. Forms and 3D arrangements of many important taxonomical characters of the euryalids were scrutinized by µCT in high enough resolution for taxonomic description of ophiuroids.

Non-destructive morphological observations of the fleshy brittle star, Asteronyx loveni using micro-computed tomography (Echinodermata, Ophiuroidea, Euryalida

Directory of Open Access Journals (Sweden)

Massanori Okanishi

2017-03-01

Full Text Available The first morphological observation of a euryalid brittle star, Asteronyx loveni, using non-destructive X-ray micro-computed tomography (µCT was performed. The body of euryalids is covered by thick skin, and it is very difficult to observe the ossicles without dissolving the skin. Computed tomography with micrometer resolution (approximately 4.5–15.4 µm was used to construct 3D images of skeletal ossicles and soft tissues in the ophiuroid’s body. Shape and positional arrangement of taxonomically important ossicles were clearly observed without any damage to the body. Detailed pathways inside the vertebral ossicles, lateral arm plates, and arm spines for passage of nerves and water vascular structures were observed. Inter-vertebral muscles were also observed. Forms and 3D arrangements of many important taxonomical characters of the euryalids were scrutinized by µCT in high enough resolution for taxonomic description of ophiuroids.

Computed tomography of cryogenic cells

International Nuclear Information System (INIS)

Schneider, Gerd; Anderson, E.; Vogt, S.; Knochel, C.; Weiss, D.; LeGros, M.; Larabell, C.

2001-01-01

Due to the short wavelengths of X-rays and low numerical aperture of the Fresnel zone plates used as X-ray objectives, the depth of field is several microns. Within the focal depth, imaging a thick specimen is to a good approximation equivalent to projecting the specimen absorption. Therefore, computed tomography based on a tilt series of X-ray microscopic images can be used to reconstruct the local linear absorption coefficient and image the three-dimensional specimen structure. To preserve the structural integrity of biological objects during image acquisition, microscopy is performed at cryogenic temperatures. Tomography based on X-ray microscopic images was applied to study the distribution of male specific lethal 1 (MSL-1), a nuclear protein involved in dosage compensation in Drosophila melanogaster, which ensures that males with single X chromosome have the same amount of most X-linked gene products as females with two X chromosomes. Tomographic reconstructions of X-ray microscopic images were used to compute the local three-dimensional linear absorption coefficient revealing the arrangement of internal structures of Drosophila melanogaster cells. Combined with labelling techniques, nanotomography is a new technique to study the 3D distribution of selected proteins inside whole cells. We want to improve this technique with respect to resolution and specimen preparation. The resolution in the reconstruction can be significantly improved by reducing the angular step size to collect more viewing angles, which requires an automated data acquisition. In addition, fast-freezing with liquid ethane instead of cryogenic He gas will be applied to improve the vitrification of the hydrated samples. We also plan to apply cryo X-ray nanotomography in order to study different types of cells and their nuclear protein distributions

Basic studies of radiation image diagnosis in veterinary medicine, 1: Comparison of the resolution of computed tomography, scanography and conventional radiography in an equine thoracic phantom

International Nuclear Information System (INIS)

Shida, T.; Suganuma, T.; Hashizume, T.

1984-01-01

In radiography of the thorax and abdomen of a large animal, the extreme thickness of the body causes a large amount of scattered radiation, which makes it difficult to obtain sharp images. The image resolutions of radiographs obtained by applying conventional radiography, scanography and computed tomography [CT] on an equine thoracic phantom were compared. Tubes of various inside diameters, used to simulate the pulmonary vessels were placed in an equine thoracic phantom and radiographed by CT, scanography and conventional radiography so as to compare the various degrees of resolution of the images of the tubes obtained by these methods. CT and scanography both gave a higher resolution index than conventional radiography, and both provided recognizable images of tubes < 2 mm in diameter, which conventional radiography failed to do. Scanography and CT can be used to obtain high-quality images of the thorax and abdomen of large animals. The image quality was compared using the resolution index (RI). The RI would be a wholly practical and comprehensive index for resolution because it includes 3 factors, contrast, sharpness and magnification, and yet is easy to calculate

Fluorodeoxyglucose positron emission tomography/computed tomography findings in a patient with cerebellar mutism after operation in posterior fossa

Directory of Open Access Journals (Sweden)

Gonca Kara Gedik

2017-03-01

Full Text Available Cerebellar mutism is a transient period of speechlessness that evolves after posterior fossa surgery in children. Although direct cerebellar and brain stem injury and supratentorial dysfunction have been implicated in the mediation of mutism, the pathophysiological mechanisms involved in the evolution of this kind of mutism remain unclear. Magnetic resonance imaging revealed dentatothalamocortical tract injuries and single photon emission computed tomography showed cerebellar and cerebral hypoperfusion in patients with cerebellar mutism. However, findings with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT in this group of patients have not been documented previously. In this clinical case, we report a patient who experienced cerebellar mutism after undergoing a posterior fossa surgery. Right cerebellar and left frontal lobe hypometabolism was shown using FDG PET/CT. The FDG metabolism of both the cerebellum and the frontal lobe returned to normal levels after the resolution of the mutism symptoms.

Density gradients in ceramic pellets measured by computed tomography

International Nuclear Information System (INIS)

Sawicka, B.D.; Palmer, B.J.F.

1986-07-01

Density gradients are of fundamental importance in ceramic processing and computed tomography (CT) can provide accurate measurements of density profiles in sintered and unsintered ceramic parts. As a demonstration of this potential, the density gradients in an unsintered pellet pressed from an alumina powder were measured by CT scanning. To detect such small density gradients, the CT images must have good density resolution and be free from beam-hardening effects. This was achieved by measuring high-contrast (low-noise) images with the use of an Ir-192 isotopic source. A beam-hardening correction was applied. The resulting images are discussed relative to the transmission of forces through the powder mass during the pelletizing process

Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI.

Science.gov (United States)

Yoon, Haesung; Yoon, Dahye; Yun, Mijin; Choi, Ji Soo; Park, Vivian Youngjean; Kim, Eun-Kyung; Jeong, Joon; Koo, Ja Seung; Yoon, Jung Hyun; Moon, Hee Jung; Kim, Suhkmann; Kim, Min Jung

2016-01-01

Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters. Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32-75 years) with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1) were suspicious for malignancy on mammography or ultrasound (US), 2) were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB) 3) underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE) and diffusion-weighted imaging (DWI) and positron emission tomography-computed tomography (PET-CT), and 4) had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER), maximum standardized FDG uptake value (SUV max), apparent diffusion coefficient (ADC), and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA) to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters. In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in all cases. Multiple metabolites showed

Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI.

Directory of Open Access Journals (Sweden)

Haesung Yoon

Full Text Available Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS magnetic resonance spectroscopy (MRS and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters.Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32-75 years with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1 were suspicious for malignancy on mammography or ultrasound (US, 2 were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB 3 underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE and diffusion-weighted imaging (DWI and positron emission tomography-computed tomography (PET-CT, and 4 had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER, maximum standardized FDG uptake value (SUV max, apparent diffusion coefficient (ADC, and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters.In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in all cases. Multiple metabolites

Quality control and radioprotection in dental cone beam computed tomography - case study

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Ligiane C.N.; Ferreira, Nadya M.P.D., E-mail: lnadya@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

2011-07-01

The radiological protection in medical and odontologic radiology follows The Order (Portaria) 453/98 of the Ministry of Health, which presents the minimum set of tests for the constancy X-ray equipment. These tests follow the procedures set forth in the Resolution no. 64, the National Agency for Sanitary Vigilance. This work aims to show a study on dental cone beam computed tomography (CBCT), evaluating the physical parameters that influence the performance and image quality and presenting the appropriate tests to this new system. The authors analyzed the tests specific for computed tomography (CT) of the Resolution no. 64, feasibility assessment of them and if their interpretations are compatible with CBCT. Once determined if testing is feasible, compare with those presented in the manual provided by the equipment manufacturer. The CT scanner used was the Mini-Cat Tomography Scanner Xoran Technologies of KAVO. In the study it was verified that four tests could be reproduced in CBCT: noise, accuracy and uniformity in the number of CT of water and spatial resolution. Considering experimental data, the methodology and tolerance of manufacturer for the first two tests were more appropriate. For the uniformity test of the CT number, we recommend using the phantom quality control. Three new tests were suggested to be made in the quality control of the Cone Beam: linearity, artifacts and alignment of the beam. (author)

Quality control and radioprotection in dental cone beam computed tomography - case study

International Nuclear Information System (INIS)

Rodrigues, Ligiane C.N.; Ferreira, Nadya M.P.D.

2011-01-01

The radiological protection in medical and odontologic radiology follows The Order (Portaria) 453/98 of the Ministry of Health, which presents the minimum set of tests for the constancy X-ray equipment. These tests follow the procedures set forth in the Resolution no. 64, the National Agency for Sanitary Vigilance. This work aims to show a study on dental cone beam computed tomography (CBCT), evaluating the physical parameters that influence the performance and image quality and presenting the appropriate tests to this new system. The authors analyzed the tests specific for computed tomography (CT) of the Resolution no. 64, feasibility assessment of them and if their interpretations are compatible with CBCT. Once determined if testing is feasible, compare with those presented in the manual provided by the equipment manufacturer. The CT scanner used was the Mini-Cat Tomography Scanner Xoran Technologies of KAVO. In the study it was verified that four tests could be reproduced in CBCT: noise, accuracy and uniformity in the number of CT of water and spatial resolution. Considering experimental data, the methodology and tolerance of manufacturer for the first two tests were more appropriate. For the uniformity test of the CT number, we recommend using the phantom quality control. Three new tests were suggested to be made in the quality control of the Cone Beam: linearity, artifacts and alignment of the beam. (author)

Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography

Science.gov (United States)

Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

2015-01-01

Abstract. A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography (μCT) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In μCT, the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer–Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to 606  μm in SS-OCT. A correlation between μCT and SS-OCT was found regarding lesion depth (R=0.81, p<0.001) and also surface layer thickness (R=0.76, p<0.005). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution μCT without the use of x-ray. PMID:26158079

Ex-situ X-ray computed tomography data for a non-crimp fabric based glass fibre composite under fatigue loading

DEFF Research Database (Denmark)

Jespersen, Kristine Munk; Mikkelsen, Lars Pilgaard

2017-01-01

The data published with this article are high resolution X-ray computed tomography (CT) data obtained during an ex-situ fatigue test of a coupon test specimen made from a non-crimp fabric based glass fibre composite similar to those used for wind turbine blades. The fatigue test was interrupted...

Detectors for high resolution dynamic pet

International Nuclear Information System (INIS)

Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.

1983-05-01

This report reviews the motivation for high spatial resolution in dynamic positron emission tomography of the head and the technical problems in realizing this objective. We present recent progress in using small silicon photodiodes to measure the energy deposited by 511 keV photons in small BGO crystals with an energy resolution of 9.4% full-width at half-maximum. In conjunction with a suitable phototube coupled to a group of crystals, the photodiode signal to noise ratio is sufficient for the identification of individual crystals both for conventional and time-of-flight positron tomography

Integral diagnosis of coronary atherosclerosis by coronary multidetector computed tomography and by invasive coronary angiography

International Nuclear Information System (INIS)

Llerena Rojas, Luis Roberto; Llerena Rojas, Lorenzo D; Mendoza Rodriguez, Vladimir

2013-01-01

Coronary angiography by multidetector computed tomography (CMDCT) visualizes the wall and lumen of coronary arteries. Invasive coronary angiography (INVCA) only visualizes the arterial lumen but with better resolution

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

DEFF Research Database (Denmark)

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

2011-01-01

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

Advanced proton imaging in computed tomography

CERN Document Server

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

2015-01-01

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

Computer tomography of the neurocranium.

Science.gov (United States)

Liliequist, B; Forssell, A

1976-07-01

The experience with computer tomography of the neurocranium in 300 patients submitted for computer tomography of the brain is reported. The more appropriate projections which may be obtained with the second generation of scanners in combination with an elaborated reconstruction technique seem to constitute a replacement of conventional skull films.

Protean appearance of craniopharyngioma on computed tomography

International Nuclear Information System (INIS)

Danziger, A.; Price, H.I.

1979-01-01

Craniopharyngiomas present a diverse appearance on computed tomography. Histological diagnosis is not always possible, but computed tomography is of great assistance in the delineation of the tumour as well as of the degree of associated hydrocephalus. Computed tomography also enables rapid non-invasive follow-up after surgery or radiotherapy, or both

Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

OpenAIRE

Yao, Junjie; Xia, Jun; Maslov, Konstantin I.; Nasiriavanaki, Mohammadreza; Tsytsarev, Vassiliy; Demchenko, Alexei V.; Wang, Lihong V.

2012-01-01

We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood–brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for ...

Analytical evaluation of the signal and noise propagation in x-ray differential phase-contrast computed tomography

International Nuclear Information System (INIS)

Raupach, Rainer; Flohr, Thomas G

2011-01-01

We analyze the signal and noise propagation of differential phase-contrast computed tomography (PCT) compared with conventional attenuation-based computed tomography (CT) from a theoretical point of view. This work focuses on grating-based differential phase-contrast imaging. A mathematical framework is derived that is able to analytically predict the relative performance of both imaging techniques in the sense of the relative contrast-to-noise ratio for the contrast of any two materials. Two fundamentally different properties of PCT compared with CT are identified. First, the noise power spectra show qualitatively different characteristics implying a resolution-dependent performance ratio. The break-even point is derived analytically as a function of system parameters such as geometry and visibility. A superior performance of PCT compared with CT can only be achieved at a sufficiently high spatial resolution. Second, due to periodicity of phase information which is non-ambiguous only in a bounded interval statistical phase wrapping can occur. This effect causes a collapse of information propagation for low signals which limits the applicability of phase-contrast imaging at low dose.

Bronchial asthma: correlation of high resolution computerized tomography findings with clinical data; Asma bronquica: correlacao de achados em tomografia computadorizada de alta resolucao com dados clinicos

Energy Technology Data Exchange (ETDEWEB)

Mogami, Roberto [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Servico de Radiologia; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Kirk, Kennedy; Capone, Domenico [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Servico de Pneumologia; Daltro, Pedro [Instituto Fernandes Figueira, Rio de Janeiro, RJ (Brazil). Servico de Radiologia

1999-04-01

In this work we did a sectional study of 31 asthmatic patients with several levels of disease severity, which were submitted to high resolution computed tomography of the thorax and spirometry, between the months of July, 1995 and August, 1997. The tomographic findings were correlated with the clinical classification of the patients and the most frequent tomographic findings were bronchial wall thickening, bronchial dilatation, air trapping, centrilobular opacities, cicatricial linear shadows, mucoid impaction, emphysema and atelectasis. In asthmatic patients of long duration we observed small airway disease and irreversible lesions as the predominant findings. In smoking patients there was no high frequency of emphysema. (author)

Evaluation of a 99Tcm bound brain scanning agent for single photon emission computed tomography

DEFF Research Database (Denmark)

Andersen, A R; Hasselbalch, S G; Paulson, O B

1986-01-01

D,L HM-PAO-99Tcm (PAO) is a lipophilic tracer complex which is avidly taken up by the brain. We have compared the regional distribution of PAO with regional cerebral blood flow (CBF). CBF was measured by single photon emission computed tomography (SPECT) by Tomomatic 64 after 133Xe inhalation in 41...... patients. With the same SPECT the distribution of PAO was measured after intravenous injection. High resolution (HR) and low resolution (LR) studies were performed yielding a resolution of 6-10 mm (HR) and 15-20 mm (LR). PAO images showed close resemblance to 133Xe CBF tomograms. Only 20 per cent...... of the (decay corrected) brain counts were lost during 24 hours....

Fibrose maciça progressiva em trabalhadores expostos à sílica: achados na tomografia computadorizada de alta resolução Progressive massive fibrosis in silica-exposed workers: high-resolution computed tomography findings

Directory of Open Access Journals (Sweden)

Ângela Santos Ferreira

2006-12-01

Full Text Available OBJETIVO: Avaliar as características radiológicas das massas conglomeradas pela tomografia computadorizada de alta resolução de tórax. MÉTODOS: Foram selecionados 75 pacientes silicóticos, a maioria jateadores de areia, portadores de fibrose maciça progressiva, atendidos no Hospital Universitário Antônio Pedro entre 1986 e 2004. Os pacientes foram submetidos a avaliação clínica, radiografia simples de tórax e tomografia computadorizada de alta resolução. RESULTADOS: Mais da metade dos pacientes com silicose complicada mostrou na radiografia de tórax grandes opacidades dos tipos B e C, denotando a gravidade da doença nesses pacientes. Dos 75 casos, apenas um apresentou massa unilateral simulando câncer de pulmão. Quarenta e quatro pacientes realizaram tomografia computadorizada de alta resolução do tórax. As massas predominaram nos terços superiores e posteriores (88,6%. Broncograma aéreo e calcificações no interior das massas foram observados em 70,4% e 63,8% dos casos, respectivamente. História de tuberculose foi relatada em 52% dos pacientes estudados. CONCLUSÃO: Na grande maioria dos casos as massas eram bilaterais, predominando nas regiões póstero-superiores dos pulmões, com broncogramas aéreos e calcificações de permeio. Associação com calcificações linfonodais foi um achado freqüente. A exposição a elevadas concentrações de poeira e a tuberculose foram consideradas fatores de risco para o desenvolvimento da fibrose maciça progressiva.OBJECTIVE: To evaluate the radiological characteristics of conglomerate masses using high-resolution computed tomography of the chest. METHODS: From among the patients treated between 1986 and 2004 at the Antonio Pedro University Hospital, 75 patients with silicosis and massive fibrosis, most working in the field of sandblasting, were selected for study. These patients were submitted to a clinical evaluation, chest X-ray and high-resolution computed tomography of

In vivo high resolution human corneal imaging using full-field optical coherence tomography.

Science.gov (United States)

Mazlin, Viacheslav; Xiao, Peng; Dalimier, Eugénie; Grieve, Kate; Irsch, Kristina; Sahel, José-Alain; Fink, Mathias; Boccara, A Claude

2018-02-01

We present the first full-field optical coherence tomography (FFOCT) device capable of in vivo imaging of the human cornea. We obtained images of the epithelial structures, Bowman's layer, sub-basal nerve plexus (SNP), anterior and posterior stromal keratocytes, stromal nerves, Descemet's membrane and endothelial cells with visible nuclei. Images were acquired with a high lateral resolution of 1.7 µm and relatively large field-of-view of 1.26 mm x 1.26 mm - a combination, which, to the best of our knowledge, has not been possible with other in vivo human eye imaging methods. The latter together with a contactless operation, make FFOCT a promising candidate for becoming a new tool in ophthalmic diagnostics.

New solutions and applications of 3D computer tomography image processing

Science.gov (United States)

Effenberger, Ira; Kroll, Julia; Verl, Alexander

2008-02-01

As nowadays the industry aims at fast and high quality product development and manufacturing processes a modern and efficient quality inspection is essential. Compared to conventional measurement technologies, industrial computer tomography (CT) is a non-destructive technology for 3D-image data acquisition which helps to overcome their disadvantages by offering the possibility to scan complex parts with all outer and inner geometric features. In this paper new and optimized methods for 3D image processing, including innovative ways of surface reconstruction and automatic geometric feature detection of complex components, are presented, especially our work of developing smart online data processing and data handling methods, with an integrated intelligent online mesh reduction. Hereby the processing of huge and high resolution data sets is guaranteed. Besides, new approaches for surface reconstruction and segmentation based on statistical methods are demonstrated. On the extracted 3D point cloud or surface triangulation automated and precise algorithms for geometric inspection are deployed. All algorithms are applied to different real data sets generated by computer tomography in order to demonstrate the capabilities of the new tools. Since CT is an emerging technology for non-destructive testing and inspection more and more industrial application fields will use and profit from this new technology.

Application of C-arm computed tomography in cardiology

International Nuclear Information System (INIS)

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

2009-01-01

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

Computed tomography of the petrous bone in otosclerosis and Meniere's disease

International Nuclear Information System (INIS)

Groot, J.A.M. de.

1987-01-01

The aim of this investigation was to examine if, in the case of otosclerosis and Meniere's disease, one could obtain more information with high resolution computer tomography than with conventional polytomography. In the first part of this thesis a brief survey of some principles of computer tomography is given and a computer tomographic atlas of the normal petrous bone in the otoradiologic planes used in this study. In the introduction of the second part some aspects of otosclerose are discussed (definition, clinical aspects). Subsequently a treatment is given of a part of the histopathology referring to the otospongiotic and otosclerotic changes in the labyrinthine capsule. A survey is given of preceding studies on the petrous bone in the case of otosclerosis; in these studies mostly classical planigraphic techniques were employed. In the third part some general aspects of Meniere's disease are discussed: definition, incidence, clinical aspects and pathophysiology. It is assumed that the symptoms of Meniere's disease are caused by an overpressure in the endolymphatic areas of the labyrinthum ('hydrops'), however till now a proof for this is still not given. The ductus endolympathicus, which passes through a channel in the petrous bone (the vestibular aqueduct), plays a role in the drainage of endolymph. Stagnation of this drainage could cause hydrops. (Auth.)

Computed tomography in renal trauma

International Nuclear Information System (INIS)

Brueck, W.; Eisenberger, F.; Buck, J.

1981-01-01

In a group of 19 patients suffering from flank trauma and gross hematuria the diagnostic value of angiography was compared with that of computed tomography. The cases that underwent both tests were found to have the some diagnosis of rupture of the kidney. Typical CT-findings in kidney rupture are demonstrated. Whereas angiography presents an exact picture of the arterial system of the kidney, including its injures computed tomography reveals the extent of organ lesons by showing extra- and intrarenal hematomas. If surgery is planned angiography is still mandatory, whereby the indication is largely determined by the clinical findings. Computed tomography as a non-invasive method is equally suitable for follow-ups. (orig.) [de

A stationary computed tomography system with cylindrically distributed sources and detectors.

Science.gov (United States)

Chen, Yi; Xi, Yan; Zhao, Jun

2014-01-01

The temporal resolution of current computed tomography (CT) systems is limited by the rotation speed of their gantries. A helical interlaced source detector array (HISDA) CT, which is a stationary CT system with distributed X-ray sources and detectors, is presented in this paper to overcome the aforementioned limitation and achieve high temporal resolution. Projection data can be obtained from different angles in a short time and do not require source, detector, or object motion. Axial coverage speed is increased further by employing a parallel scan scheme. Interpolation is employed to approximate the missing data in the gaps, and then a Katsevich-type reconstruction algorithm is applied to enable an approximate reconstruction. The proposed algorithm suppressed the cone beam and gap-induced artifacts in HISDA CT. The results also suggest that gap-induced artifacts can be reduced by employing a large helical pitch for a fixed gap height. HISDA CT is a promising 3D dynamic imaging architecture given its good temporal resolution and stationary advantage.

Interactively variable isotropic resolution in computed tomography

International Nuclear Information System (INIS)

Lapp, Robert M; Kyriakou, Yiannis; Kachelriess, Marc; Wilharm, Sylvia; Kalender, Willi A

2008-01-01

An individual balancing between spatial resolution and image noise is necessary to fulfil the diagnostic requirements in medical CT imaging. In order to change influencing parameters, such as reconstruction kernel or effective slice thickness, additional raw-data-dependent image reconstructions have to be performed. Therefore, the noise versus resolution trade-off is time consuming and not interactively applicable. Furthermore, isotropic resolution, expressed by an equivalent point spread function (PSF) in every spatial direction, is important for the undistorted visualization and quantitative evaluation of small structures independent of the viewing plane. Theoretically, isotropic resolution can be obtained by matching the in-plane and through-plane resolution with the aforementioned parameters. Practically, however, the user is not assisted in doing so by current reconstruction systems and therefore isotropic resolution is not commonly achieved, in particular not at the desired resolution level. In this paper, an integrated approach is presented for equalizing the in-plane and through-plane spatial resolution by image filtering. The required filter kernels are calculated from previously measured PSFs in x/y- and z-direction. The concepts derived are combined with a variable resolution filtering technique. Both approaches are independent of CT raw data and operate only on reconstructed images which allows for their application in real time. Thereby, the aim of interactively variable, isotropic resolution is achieved. Results were evaluated quantitatively by measuring PSFs and image noise, and qualitatively by comparing the images to direct reconstructions regarded as the gold standard. Filtered images matched direct reconstructions with arbitrary reconstruction kernels with standard deviations in difference images of typically between 1 and 17 HU. Isotropic resolution was achieved within 5% of the selected resolution level. Processing times of 20-100 ms per frame

[Computed tomography of the heart

DEFF Research Database (Denmark)

Kristensen, T.S.; Kofoed, K.F.; der, Recke P. von

2009-01-01

Noninvasive evaluation of the coronary arteries by multi-detector row computed tomography is a promising new alternative to conventional invasive coronary angiography. This article describes the technical background, methods, limitations and clinical applications and reviews current literature...... that compares the diagnostic accuracy of multi-detector row computed tomography with that of coronary angiography Udgivelsesdato: 2009/4/6...

Computing with high-resolution upwind schemes for hyperbolic equations

International Nuclear Information System (INIS)

Chakravarthy, S.R.; Osher, S.; California Univ., Los Angeles)

1985-01-01

Computational aspects of modern high-resolution upwind finite-difference schemes for hyperbolic systems of conservation laws are examined. An operational unification is demonstrated for constructing a wide class of flux-difference-split and flux-split schemes based on the design principles underlying total variation diminishing (TVD) schemes. Consideration is also given to TVD scheme design by preprocessing, the extension of preprocessing and postprocessing approaches to general control volumes, the removal of expansion shocks and glitches, relaxation methods for implicit TVD schemes, and a new family of high-accuracy TVD schemes. 21 references

Accounting for sub-resolution pores in models of water and solute transport in soils based on computed tomography images: Are we there yet?

Science.gov (United States)

Baveye, Philippe C.; Pot, Valérie; Garnier, Patricia

2017-12-01

In the last decade, X-ray computed tomography (CT) has become widely used to characterize the geometry and topology of the pore space of soils and natural porous media. Regardless of the resolution of CT images, a fundamental problem associated with their use, for example as a starting point in simulation efforts, is that sub-resolution pores are not detected. Over the last few years, a particular type of modeling method, known as ;Grey; or ;Partial Bounce Back; Lattice-Boltzmann (LB), has been adopted by increasing numbers of researchers to try to account for sub-resolution pores in the modeling of water and solute transport in natural porous media. In this short paper, we assess the extent to which Grey LB methods indeed offer a workable solution to the problem at hand. We conclude that, in spite of significant computational advances, a major experimental hurdle related to the evaluation of the penetrability of sub-resolution pores, is blocking the way ahead. This hurdle will need to be cleared before Grey LB can become a credible option in the microscale modeling of soils and sediments. A necessarily interdisciplinary effort, involving both modelers and experimentalists, is needed to clear the path forward.

The value of computed tomography in ''sciatica''

International Nuclear Information System (INIS)

Boehm-Jurkovic, H.; Hammer, B.

1981-01-01

13 cases of therapy-resistant lumboischialgia without herniated disk, caused in 12 cases by a tumour and in 1 case by an abscess, were examined by computed tomography of the lumbar and pelvic region. This method is indicated immediately after insufficient results of conventional X-ray methods (including tomography) and of lumbosacral radiculography. The computed tomography is indispensable also in patients with ''sciatica'' with a known malignoma. The information given by computed tomography is essential for the therapy planning. (author)

Computed tomography in intracranial malignant lymphoma

Energy Technology Data Exchange (ETDEWEB)

Naruse, S; Odake, G; Fujimoto, M; Yamaki, T; Mizukawa, N [Kyoto Prefectural Univ. of Medicine (Japan)

1978-09-01

Malignant lymphoma of the central nervous system has been found more and more often in recent years, partly because of the increased use of radiation and such drugs as steroids and antibiotics. However, the definite diagnosis of this disease is difficult until histological verification has been done by operation or autopsy. Since the revolutionary development of computed tomography, however, several reports have been presented, on the computed tomography of malignant lymphoma of the thorax and abdomen. Nevertheless, only a few cases of intracranial malignant lymphoma have been reported. The purpose of this paper, using four patients, is to emphasize the value of computed tomography in the diagnosis of intracranial malignant lymphoma. The characteristic CT findings of intracranial malignant lymphoma may be summarized follows: (1) the tumors are demonstrated to be well-defined, nodular-shaped, and homogenous isodensity - or slightly high-density - lesions in plain scans, and the tumors homogenously increase in density upon contrast enhancement; (2) the disease always has multifocal intracranial lesions, which are shown simultaneously or one after another, and (3) perifocal edema is prominent around the tumors in the cerebral hemisphere.

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

Science.gov (United States)

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

2018-01-01

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

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

Bone Microarchitecture and Estimated Strength in 499 Adult Danish Women and Men: A Cross-Sectional, Population-Based High-Resolution Peripheral Quantitative Computed Tomographic Study on Peak Bone Structure

DEFF Research Database (Denmark)

Hansen, Stinus; Shanbhogue, V.; Folkestad, L.

2014-01-01

High-resolution peripheral quantitative computed tomography (HR-pQCT) allows in vivo assessment of cortical and trabecular bone mineral density (BMD), geometry, and microarchitecture at the distal radius and tibia in unprecedented detail. In this cross-sectional study, we provide normative and de...... and descriptive HR-pQCT data from a large population-based sample of Danish Caucasian women and men (n = 499) aged 20-80 years. In young adults (...

Investigation of optimal display size for detecting ground-glass opacity on high resolution computed tomography using a new digital contrast-detail phantom

International Nuclear Information System (INIS)

Yamaguchi, Michihiro; Fujita, Hideki; Bessho, Yuichi; Inoue, Tatsuro; Asai, Yoshiyuki; Murase, Kenya

2011-01-01

The purpose of this study was to clarify the relationship between display sizes of high resolution computed tomography (HRCT) images for detecting ground-glass opacity (GGO) and observer performance using a digital contrast-detail (d-CD) phantom. A structure of the d-CD phantom was determined on the basis of the actual images of GGOs and background noises of 22 patients who were diagnosed as GGO by chest HRCT. The d-CD phantom has a 512 × 512 matrix in size and has total of 100 holes: the diameter of these holes increases stepwise from 2 to 20 pixels with 2 pixels interval in a vertical direction and the CT value varies stepwise from 2 to 200 HU in a horizontal direction. The observer performance study was carried out for three different display sizes (30 cm × 30 cm as an enlarged size, 13 cm × 13 cm as an original size, and 7 cm × 7 cm as a reduced size) using a 2-megapixels LCD monitor, and it was analyzed using Friedman and Wilcoxon statistical tests. As a result, the observer performance for the original display and the reduced display sizes was superior to that for the enlarged size (P = 0.006 and 0.037 for the original display and the reduced display sizes, respectively), whereas there was no significant difference between the original display and reduced display sizes (P = 0.77). The d-CD phantom enables a short-term evaluation of observer performance and is useful in analyzing relationship between display size and observer performance.

High-resolution CT of lymphoid interstitial pneumonia

International Nuclear Information System (INIS)

Vilgrain, V.; Frija, J.; Yana, C.; Couderc, L.J.; David, M.; Clauvel, J.P.; Laval-Jeantet, M.

1989-01-01

Three patients with lymphoid interstitial pneumonia (two HIV 1+ patients with chronic lymphadenopathic syndromes and one with a not-characterized autoimmune disease) have been studied with high-resolution computed tomography (HR-CT). This technique reveals septal lines, small reticulonodular opacities, polyhedral micronodular opacities, 'ground-glass' opacities and a dense, subpleural, curved broken line in one patient. The lesions dominate in the bases of the lungs. They are not characteristic for lymphoid interstitial pneumonia. If a patient presents with a chronic lymphadenopathic syndrome, the diagnosis of an opportunistic infection should not be automatically made, since the syndrome can be caused by lymphoid interstitial pneumonia [fr

Computer tomography in the diagnosis of liver diseases

International Nuclear Information System (INIS)

Petkov, D.; Zhelyazkov, S.; Nedelkov, G.

1983-01-01

The modern achievements in the clinical study and diagnosis of liver diseases has definitely been associated with the application of whole body computer tomography (CT) in the practice. The diagnostic possibilities of the method come from high contrast and spacial disjunctive capabilities. Visualization of local lesions is associated with their size and the differences in their densitometric compactness from that of the normal parenchyma. The advantages of computer tomography in the diagnosis of liver diseases is discussed. They are associated with the possibilities for densitometric analysis of the pathologic changes, which opens a way for a probable qualitative diagnosis. Diffuse processes in the liver are relative indication for performing computer tomography. Examination under conditions of contrast amplification is indicated in cases when the nature of the lesion has to be specified and a ''negative'' result does not concur with the clinical manifestations. (authors)

Bronchoalveolar lavage cellular analyses in conjunction with high-resolution computed tomography imaging as a diagnostic intervention for patients with suspected interstitial lung disease

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Ammaiyappan Chockalingam

2016-01-01

Full Text Available Background: Bronchoalveolar lavage (BAL has gained acceptance for diagnosis of Interstitial lung disease (ILD. The advent of high-resolution computed tomography (HRCT has reduced the clinical utility of BAL. This work has utilized the recommendations of the American Thoracic Society (ATS to optimize BAL and the findings have been associated with clinical examination and HRCT to precisely narrow down the cause of ILD. Materials and Methods: BAL was performed on ILD suspects at the target site chosen based on HRCT. The procedure, transport, processing, and analysis of BAL fluid were performed as per the ATS guidelines. The clinical data, HRCT findings and BAL report were used to narrow down the diagnosis of ILD. The statistical analysis was performed to assess the significance. Results: The BAL procedure was optimized as per the recommendations of the ATS. In a cohort of 50 patients, Idiopathic pulmonary fibrosis, (8 hypersensitivity pneumonitis, (17 connective tissue disorder, (9 sarcoidosis, (3 pneumoconiosis, (5 acute respiratory distress syndrome, (2 eosinophilic lung disease (2 and lymphangitic carcinomatosa, (2 aspiration bronchiolitis (1 and pulmonary histiocytosis (1 were diagnosed. Statistically significant variation in differential counts was found in different ILDs. The different ILDs were classified based on the criteria described by the ATS. Clinical Significance: BAL along with clinical and HRCT findings improved the diagnostic accuracy by incorporating, the acute or chronic nature of the disease and the cause for acute exacerbation, which helped in the better management of ILDs.

High-resolution computed tomography findings of influenza virus pneumonia. A comparative study between seasonal and novel (H1N1) influenza virus pneumonia

International Nuclear Information System (INIS)

Tanaka, Nobuyuki; Kunihiro, Yoshie; Matsunaga, Naofumi; Hasegawa, Shunji; Ichiyama, Takashi; Emoto, Takuya; Suda, Hiroki

2012-01-01

The purpose of this study was to evaluate the high-resolution computed tomography (HRCT) findings of novel influenza virus (n-IFV) pneumonia and compare them with the findings for seasonal (s-IFV) pneumonia. We evaluated 29 cases of pure IFV pneumonia that occurred between 1990 and 2010. We evaluated the existence, extent, and patterns of HRCT findings and compared these features between s-IFV and n-IFV. Consolidation was less frequent in s-IFV than in n-IFV (40.0 vs. 84.2%, respectively; p=0.014). Consolidation with a loss of volume was frequent in n-IFV (62.5%). There was no significant difference in the occurrence of ground-glass opacity (GGO) between s-IFV and n-IFV (100 vs. 84.2%, respectively). GGO with reticular opacities was more frequent in s-IFV than in n-IFV (70.0 vs. 25.0%, respectively; p=0.024). The frequency of nodules was not significantly different between the two groups. The mosaic pattern was more frequent in s-IFV than in n-IFV patients (80.0 vs. 15.8%, respectively; p=0.0007). Mucoid impaction was more frequent in patients with n-IFV than with s-IFV (52.6 vs. 10.0%, respectively; p=0.025). Consolidation and mucoid impaction were more frequent in n-IFV, whereas GGO with reticular opacities and a mosaic pattern occurred more frequently in s-IFV; otherwise, there were no significant differences between the two groups. (author)

[Axial computer tomography of the neurocranium (author's transl)].

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Stöppler, L

1977-05-27

Computer tomography (CT), a new radiographic examination technique, is very highly efficient, for it has high informative content with little stress for the patient. In contrast to the conventional X-ray technology, CT succeeds, by direct presentation of the structure of the soft parts, in obtaining information which comes close to that of macroscopic neuropathology. The capacity and limitations of the method at the present stage of development are reported. Computer tomography cannot displace conventional neuroradiological methods of investigation, although it is rightly presented as a screening method and helps towards selective use. Indications, technical integration and handling of CT are prerequisites for the exhaustive benefit of the excellent new technique.

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)

Towards high-resolution positron emission tomography for small volumes

International Nuclear Information System (INIS)

McKee, B.T.A.

1982-01-01

Some arguments are made regarding the medical usefulness of high spatial resolution in positron imaging, even if limited to small imaged volumes. Then the intrinsic limitations to spatial resolution in positron imaging are discussed. The project to build a small-volume, high resolution animal research prototype (SHARP) positron imaging system is described. The components of the system, particularly the detectors, are presented and brief mention is made of data acquisition and image reconstruction methods. Finally, some preliminary imaging results are presented; a pair of isolated point sources and 18 F in the bones of a rabbit. Although the detector system is not fully completed, these first results indicate that the goals of high sensitivity and high resolution (4 mm) have been realized. (Auth.)

Simultaneous Confocal Scanning Laser Ophthalmoscopy Combined with High-Resolution Spectral-Domain Optical Coherence Tomography: A Review

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Verônica Castro Lima

2011-01-01

Full Text Available We aimed to evaluate technical aspects and the clinical relevance of a simultaneous confocal scanning laser ophthalmoscope and a high-speed, high-resolution, spectral-domain optical coherence tomography (SDOCT device for retinal imaging. The principle of confocal scanning laser imaging provides a high resolution of retinal and choroidal vasculature with low light exposure. Enhanced contrast, details, and image sharpness are generated using confocality. The real-time SDOCT provides a new level of accuracy for assessment of the angiographic and morphological correlation. The combined system allows for simultaneous recordings of topographic and tomographic images with accurate correlation between them. Also it can provide simultaneous multimodal imaging of retinal pathologies, such as fluorescein and indocyanine green angiographies, infrared and blue reflectance (red-free images, fundus autofluorescence images, and OCT scans (Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany. The combination of various macular diagnostic tools can lead to a better understanding and improved knowledge of macular diseases.

Computed tomography in facial trauma

International Nuclear Information System (INIS)

Zilkha, A.

1982-01-01

Computed tomography (CT), plain radiography, and conventional tomography were performed on 30 patients with facial trauma. CT demonstrated bone and soft-tissue involvement. In all cases, CT was superior to tomography in the assessment of facial injury. It is suggested that CT follow plain radiography in the evaluation of facial trauma

Quantitative computed tomography: emphysema and airway wall thickness by sex, age and smoking

DEFF Research Database (Denmark)

Grydeland, T B; Dirksen, A; Coxson, H O

2009-01-01

We investigated how quantitative high-resolution computed tomography (HRCT) measures of emphysema and airway wall thickness (AWT) vary with sex, age and smoking history. We included 463 chronic obstructive pulmonary disease (COPD) cases and 431 controls. All included subjects were current or ex...... cases, respectively, and 0.488+/-0.028 and 0.463+/-0.025 in male and female controls, respectively. AWT decreased with increasing age in cases, and increased with the degree of current smoking in all subjects. We found significant differences in quantitative HRCT measures of emphysema and AWT between...

Prognostic significance of tumor size of small lung adenocarcinomas evaluated with mediastinal window settings on computed tomography.

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Yukinori Sakao

Full Text Available BACKGROUND: We aimed to clarify that the size of the lung adenocarcinoma evaluated using mediastinal window on computed tomography is an important and useful modality for predicting invasiveness, lymph node metastasis and prognosis in small adenocarcinoma. METHODS: We evaluated 176 patients with small lung adenocarcinomas (diameter, 1-3 cm who underwent standard surgical resection. Tumours were examined using computed tomography with thin section conditions (1.25 mm thick on high-resolution computed tomography with tumour dimensions evaluated under two settings: lung window and mediastinal window. We also determined the patient age, gender, preoperative nodal status, tumour size, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and pathological status (lymphatic vessel, vascular vessel or pleural invasion. Recurrence-free survival was used for prognosis. RESULTS: Lung window, mediastinal window, tumour disappearance ratio and preoperative nodal status were significant predictive factors for recurrence-free survival in univariate analyses. Areas under the receiver operator curves for recurrence were 0.76, 0.73 and 0.65 for mediastinal window, tumour disappearance ratio and lung window, respectively. Lung window, mediastinal window, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and preoperative nodal status were significant predictive factors for lymph node metastasis in univariate analyses; areas under the receiver operator curves were 0.61, 0.76, 0.72 and 0.66, for lung window, mediastinal window, tumour disappearance ratio and preoperative serum carcinoembryonic antigen levels, respectively. Lung window, mediastinal window, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and preoperative nodal status were significant factors for lymphatic vessel, vascular vessel or pleural invasion in univariate analyses; areas under the receiver operator curves were 0

Prognostic Significance of Tumor Size of Small Lung Adenocarcinomas Evaluated with Mediastinal Window Settings on Computed Tomography

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Sakao, Yukinori; Kuroda, Hiroaki; Mun, Mingyon; Uehara, Hirofumi; Motoi, Noriko; Ishikawa, Yuichi; Nakagawa, Ken; Okumura, Sakae

2014-01-01

Background We aimed to clarify that the size of the lung adenocarcinoma evaluated using mediastinal window on computed tomography is an important and useful modality for predicting invasiveness, lymph node metastasis and prognosis in small adenocarcinoma. Methods We evaluated 176 patients with small lung adenocarcinomas (diameter, 1–3 cm) who underwent standard surgical resection. Tumours were examined using computed tomography with thin section conditions (1.25 mm thick on high-resolution computed tomography) with tumour dimensions evaluated under two settings: lung window and mediastinal window. We also determined the patient age, gender, preoperative nodal status, tumour size, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and pathological status (lymphatic vessel, vascular vessel or pleural invasion). Recurrence-free survival was used for prognosis. Results Lung window, mediastinal window, tumour disappearance ratio and preoperative nodal status were significant predictive factors for recurrence-free survival in univariate analyses. Areas under the receiver operator curves for recurrence were 0.76, 0.73 and 0.65 for mediastinal window, tumour disappearance ratio and lung window, respectively. Lung window, mediastinal window, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and preoperative nodal status were significant predictive factors for lymph node metastasis in univariate analyses; areas under the receiver operator curves were 0.61, 0.76, 0.72 and 0.66, for lung window, mediastinal window, tumour disappearance ratio and preoperative serum carcinoembryonic antigen levels, respectively. Lung window, mediastinal window, tumour disappearance ratio, preoperative serum carcinoembryonic antigen levels and preoperative nodal status were significant factors for lymphatic vessel, vascular vessel or pleural invasion in univariate analyses; areas under the receiver operator curves were 0.60, 0.81, 0

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

Science.gov (United States)

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

2014-08-01

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

Internal Morphologies of Cycled Li-Metal Electrodes Investigated by Nano-Scale Resolution X-ray Computed Tomography.

Science.gov (United States)

Frisco, Sarah; Liu, Danny X; Kumar, Arjun; Whitacre, Jay F; Love, Corey T; Swider-Lyons, Karen E; Litster, Shawn

2017-06-07

While some commercially available primary batteries have lithium metal anodes, there has yet to be a commercially viable secondary battery with this type of electrode. Research prototypes of these cells typically exhibit a limited cycle life before dendrites form and cause internal cell shorting, an occurrence that is more pronounced during high-rate cycling. To better understand the effects of high-rate cycling that can lead to cell failure, we use ex situ nanoscale-resolution X-ray computed tomography (nano-CT) with the aid of Zernike phase contrast to image the internal morphologies of lithium metal electrodes on copper wire current collectors that have been cycled at low and high current densities. The Li that is deposited on a Cu wire and then stripped and deposited at low current density appears uniform in morphology. Those cycled at high current density undergo short voltage transients to >3 V during Li-stripping from the electrode, during which electrolyte oxidation and Cu dissolution from the current collector may occur. The effect of temperature is also explored with separate cycling experiments performed at 5 and 33 °C. The resulting morphologies are nonuniform films filled with voids that are semispherical in shape with diameters ranging from hundreds of nanometers to tens of micrometers, where the void size distributions are temperature-dependent. Low-temperature cycling elicits a high proportion of submicrometer voids, while the higher-temperature sample morphology is dominated by voids larger than 2 μm. In evaluating these morphologies, we consider the importance of nonidealities during extreme charging, such as electrolyte decomposition. We conclude that nano-CT is an effective tool for resolving features and aggressive cycling-induced anomalies in Li films in the range of 100 nm to 100 μm.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

99mTc-IgG-Lung Scintigraphy in the Assessment of Pulmonary Involvement in Interstitial Lung Disease and Its Comparison With Pulmonary Function Tests and High-Resolution Computed Tomography: A Preliminary Study

International Nuclear Information System (INIS)

Bahtouee, Mehrzad; Saberifard, Jamshid; Javadi, Hamid; Nabipour, Iraj; Malakizadeh, Hasan; Monavvarsadegh, Gholamhossein; Ilkhani Pak, Hoda; Sadeghi, Azadeh; Assadi, Majid

2015-01-01

The discrimination of inactive inflammatory processes from the active form of the disease is of great importance in the management of interstitial lung disease (ILD). The aim of this study was to determine the efficacy of 99mTc-IgG scan for the detection of severity of disease compared to high-resolution computed tomography (HRCT) and pulmonary function test (PFT). Eight known cases of ILD including four cases of Mustard gas (MG) intoxication and four patients with ILD of unknown cause were included in this study. A population of six patients without lung disease was considered as the control group. The patients underwent PFT and high-resolution computed tomography, followed by 99mTc-IgG scan. They were followed up for one year. 99mTc-IgG scan assessment of IgG uptake was accomplished both qualitatively (subjectively) and semiquantitatively. All eight ILD patients demonstrated a strong increase in 99mTc-IgG uptake in the lungs, compared to the control patients. The 99mTc-IgG scan scores were higher in the patient group (0.64[95% confidence interval(CI)=0.61-0.69])) than the control group (0.35 (0.35[95% CI=0.28-0.40]), (P<0.05)). In patients, a statistically significant positive correlation was detected between 99mTc-IgG scan and HRCT scores (Spearman’s correlation coefficient = 0.92, P < 0.008). The 99mTc-Human Immunoglobulin (HIG) scores were not significantly correlated with PFT findings (including FVC, FEV1, FEV1/FVC), O 2 saturation and age (P values > 0.05). There were no significant correlations between 99mTc-IgG score and HRCT patterns including ground glass opacity, reticular fibrosis and honeycombing (P value > 0.05). The present results confirmed that 99mTc-IgG scan could be applied to detect the severity of pulmonary involvement, which was well correlated with HRCT findings. This data also showed that the 99mTc-IgG scan might be used as a complement to HRCT in the functional evaluation of the clinical status in ILD; however, further studies are

Chest X-ray and computed tomography in the evaluation of pulmonary emphysema

International Nuclear Information System (INIS)

Irion, Klaus Loureiro; Porto, Nelson da Silva; Santana, Pablo Rydz

2007-01-01

Emphysema is a condition of the lung, characterized by the abnormal increase in the size of the airspace distal to the terminal bronchioles. Currently, emphysema is the fourth leading cause of death in the USA, affecting 14 million people. The present article describes the principal tools in the imaging diagnosis of emphysema, from the early days until the present. We describe traditional techniques, such as chest X-ray, together with the evolution of computed tomography (CT) to more advanced forms, such as high resolution CT, as well as three-dimensional CT densitometry and volumetric assessment. (author)

High-definition multidetector computed tomography for evaluation of coronary artery stents: comparison to standard-definition 64-detector row computed tomography.