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Sample records for computed tomography three-dimensional

  1. 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

  2. Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography

    International Nuclear Information System (INIS)

    Ono, Ichiro; Ohura, Takehiko; Kimura, Chu

    1989-01-01

    Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.)

  3. Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Ichiro; Ohura, Takehiko; Kimura, Chu (Hokkaido Univ., Sapporo (Japan). School of Medicine) (and others)

    1989-08-01

    Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.).

  4. Three-dimensional cranio-facial computed tomography

    International Nuclear Information System (INIS)

    Pozzi Muccelli, R.; Stagul, F.; Pozzi Muccelli, F.; Zuiani, C.; Smathers, R.

    1986-01-01

    Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy

  5. Three-dimensional cranio-facial computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi Muccelli, R; Stagul, F; Pozzi Muccelli, F; Zuiani, C; Smathers, R

    1986-01-01

    Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

  6. Analysis of secondary coxarthrosis by three dimensional computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hemmi, Osamu [Keio Univ., Tokyo (Japan). School of Medicine

    1997-11-01

    The majority of coxarthrosis in Japan is due to congenital dislocation of the hip and acetabular dysplasia. Until now coxarthrosis has been chiefly analyzed on the basis of anterior-posterior radiographs. By using three-dimensional (3D) CT, it was possible to analyze the morphological features of secondary coxarthrosis more accurately, and by using new computer graphics software, it was possible to display the contact area in the hip joint and observe changes associated with progression of the stages of the disease. There were 34 subjects (68 joints), and all of who were women. The CT data were read into a work station, and 3D reconstruction was achieved with hip surgery simulation software (SurgiPlan). Pelvic inclination, acetabular anteversion, seven parameters indicating the investment of the femoral head and two indicating the position of the hip joint in the pelvis were measured. The results showed that secondary coxarthrosis is characterized not only by lateral malposition of the hip joint according to the pelvic coordinates, but by anterior malposition as well. Many other measurements provided 3D information on the acetabular dysplasia. Many of them were correlated with the CE angle on plain radiographs. Furthermore, a strong correlation was not found between anterior and posterior acetabular coverage of the femoral head. In addition, SurgiPlan`s distance mapping function enabled 3D observation of the pattern of progression of arthrosis based on the pattern of progression of joint space narrowing. (author)

  7. Analysis of secondary coxarthrosis by three dimensional computed tomography

    International Nuclear Information System (INIS)

    Hemmi, Osamu

    1997-01-01

    The majority of coxarthrosis in Japan is due to congenital dislocation of the hip and acetabular dysplasia. Until now coxarthrosis has been chiefly analyzed on the basis of anterior-posterior radiographs. By using three-dimensional (3D) CT, it was possible to analyze the morphological features of secondary coxarthrosis more accurately, and by using new computer graphics software, it was possible to display the contact area in the hip joint and observe changes associated with progression of the stages of the disease. There were 34 subjects (68 joints), and all of who were women. The CT data were read into a work station, and 3D reconstruction was achieved with hip surgery simulation software (SurgiPlan). Pelvic inclination, acetabular anteversion, seven parameters indicating the investment of the femoral head and two indicating the position of the hip joint in the pelvis were measured. The results showed that secondary coxarthrosis is characterized not only by lateral malposition of the hip joint according to the pelvic coordinates, but by anterior malposition as well. Many other measurements provided 3D information on the acetabular dysplasia. Many of them were correlated with the CE angle on plain radiographs. Furthermore, a strong correlation was not found between anterior and posterior acetabular coverage of the femoral head. In addition, SurgiPlan's distance mapping function enabled 3D observation of the pattern of progression of arthrosis based on the pattern of progression of joint space narrowing. (author)

  8. Three-dimensional reconstruction of the biliary tract using spiral computed tomography. Three-dimensional cholangiography

    International Nuclear Information System (INIS)

    Gon, Masanori; Ogura, Norihiro; Uetsuji, Shouji; Ueyama, Yasuo

    1995-01-01

    In this study, 310 patients with benign biliary diseases, 20 with gallbladder cancer, and 8 with biliary tract carcinoma underwent spiral CT (SCT) scanning at cholangiography. Depiction rate of the shape of the conjunction site of the gallbladder and biliary tract was 27.5% by conventional intravenous cholangiography (DIC), 92.5% by ERC, and 90.0% by DIC-SCT. Abnormal cystic duct course was admitted in 14.1%. Multiplanar reconstruction by DIC-SCT enabled identification of the common bile duct and intrahepatic bile duct stone. Three-dimensional reconstruction of DIC-SCT was effective in evaluating obstruction of the anastomosis or passing condition of after hepatico-jejunostomy. Two-dimensional SCT images through PTCD tube enabled degree of hepatic invasion in bile duct cancer, and three-dimensional images were useful in grasping the morphology of the bile duct branches near the obstruction site. DIC-SCT is therefore considered a useful procedure as non-invasive examination of bile duct lesions. (S.Y.)

  9. Integration of Computed Tomography and Three-Dimensional Echocardiography for Hybrid Three-Dimensional Printing in Congenital Heart Disease.

    Science.gov (United States)

    Gosnell, Jordan; Pietila, Todd; Samuel, Bennett P; Kurup, Harikrishnan K N; Haw, Marcus P; Vettukattil, Joseph J

    2016-12-01

    Three-dimensional (3D) printing is an emerging technology aiding diagnostics, education, and interventional, and surgical planning in congenital heart disease (CHD). Three-dimensional printing has been derived from computed tomography, cardiac magnetic resonance, and 3D echocardiography. However, individually the imaging modalities may not provide adequate visualization of complex CHD. The integration of the strengths of two or more imaging modalities has the potential to enhance visualization of cardiac pathomorphology. We describe the feasibility of hybrid 3D printing from two imaging modalities in a patient with congenitally corrected transposition of the great arteries (L-TGA). Hybrid 3D printing may be useful as an additional tool for cardiologists and cardiothoracic surgeons in planning interventions in children and adults with CHD.

  10. Development of three-dimensional computed tomography system using TNRF2 of JRR-3M

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Yutaka; Mochiki, Koh-ichi [Musashi Inst. of Tech., Tokyo (Japan); Matsubayashi, Masahito

    1998-01-01

    A three-dimensional filtering engine, a convolution engine, and a back projection engine were developed for real-time signal processing of three-dimensional computed tomography. The performance of the system was measured and through-put of 0.5 second per one cross sectional data processing was attained. (author)

  11. Accuracy assessment of three-dimensional surface reconstructions of teeth from cone beam computed tomography scans

    NARCIS (Netherlands)

    Al-Rawi, B.; Hassan, B.; Vandenberge, B.; Jacobs, R.

    2010-01-01

    The use of three-dimensional (3D) models of the dentition obtained from cone beam computed tomography (CBCT) is becoming increasingly more popular in dentistry. A recent trend is to replace the traditional dental casts with digital CBCT models for diagnosis, treatment planning and simulation. The

  12. The possible usability of three-dimensional cone beam computed dental tomography in dental research

    Science.gov (United States)

    Yavuz, I.; Rizal, M. F.; Kiswanjaya, B.

    2017-08-01

    The innovations and advantages of three-dimensional cone beam computed dental tomography (3D CBCT) are continually growing for its potential use in dental research. Imaging techniques are important for planning research in dentistry. Newly improved 3D CBCT imaging systems and accessory computer programs have recently been proven effective for use in dental research. The aim of this study is to introduce 3D CBCT and open a window for future research possibilities that should be given attention in dental research.

  13. Generation of three-dimensional prototype models based on cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lambrecht, J.T.; Berndt, D.C.; Zehnder, M. [University of Basel, Department of Oral Surgery, University Hospital for Oral Surgery, Oral Radiology and Oral Medicine, Basel (Switzerland); Schumacher, R. [University of Applied Sciences Northwestern Switzerland, School of Life Sciences, Institute for Medical and Analytical Technologies, Muttenz (Switzerland)

    2009-03-15

    The purpose of this study was to generate three-dimensional models based on digital volumetric data that can be used in basic and advanced education. Four sets of digital volumetric data were established by cone beam computed tomography (CBCT) (Accuitomo, J. Morita, Kyoto, Japan). Datasets were exported as Dicom formats and imported into Mimics and Magic software programs to separate the different tissues such as nerve, tooth and bone. These data were transferred to a Polyjet 3D Printing machine (Eden 330, Object, Israel) to generate the models. Three-dimensional prototype models of certain limited anatomical structures as acquired volumetrically were fabricated. Generating three-dimensional models based on CBCT datasets is possible. Automated routine fabrication of these models, with the given infrastructure, is too time-consuming and therefore too expensive. (orig.)

  14. Generation of three-dimensional prototype models based on cone beam computed tomography

    International Nuclear Information System (INIS)

    Lambrecht, J.T.; Berndt, D.C.; Zehnder, M.; Schumacher, R.

    2009-01-01

    The purpose of this study was to generate three-dimensional models based on digital volumetric data that can be used in basic and advanced education. Four sets of digital volumetric data were established by cone beam computed tomography (CBCT) (Accuitomo, J. Morita, Kyoto, Japan). Datasets were exported as Dicom formats and imported into Mimics and Magic software programs to separate the different tissues such as nerve, tooth and bone. These data were transferred to a Polyjet 3D Printing machine (Eden 330, Object, Israel) to generate the models. Three-dimensional prototype models of certain limited anatomical structures as acquired volumetrically were fabricated. Generating three-dimensional models based on CBCT datasets is possible. Automated routine fabrication of these models, with the given infrastructure, is too time-consuming and therefore too expensive. (orig.)

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  16. Three Dimensional Digital Sieving of Asphalt Mixture Based on X-ray Computed Tomography

    OpenAIRE

    Chichun Hu; Jiexian Ma; M. Emin Kutay

    2017-01-01

    In order to perform three-dimensional digital sieving based on X-ray computed tomography images, the definition of digital sieve size (DSS) was proposed, which was defined as the minimum length of the minimum bounding squares of all possible orthographic projections of an aggregate. The corresponding program was developed to reconstruct aggregate structure and to obtain DSS. Laboratory experiments consisting of epoxy-filled aggregate specimens were conducted to investigate the difference betw...

  17. Terahertz computed tomography in three-dimensional using a pyroelectric array detector

    Science.gov (United States)

    Li, Bin; Wang, Dayong; Zhou, Xun; Rong, Lu; Huang, Haochong; Wan, Min; Wang, Yunxin

    2017-05-01

    Terahertz frequency range spans from 0.1 to 10 THz. Terahertz radiation can penetrate nonpolar materials and nonmetallic materials, such as plastics, wood, and clothes. Then the feature makes the terahertz imaging have important research value. Terahertz computed tomography makes use of the penetrability of terahertz radiation and obtains three-dimensional object projection data. In the paper, continuous-wave terahertz computed tomography with a pyroelectric array detectoris presented. Compared with scanning terahertz computed tomography, a pyroelectric array detector can obtain a large number of projection data in a short time, as the acquisition mode of the array pyroelectric detector omit the projection process on the vertical and horizontal direction. With the two-dimensional cross-sectional images of the object are obtained by the filtered back projection algorithm. The two side distance of the straw wall account for 80 pixels, so it multiplied by the pixel size is equal to the diameter of the straw about 6.4 mm. Compared with the actual diameter of the straw, the relative error is 6%. In order to reconstruct the three-dimensional internal structure image of the straw, the y direction range from 70 to 150 are selected on the array pyroelectric detector and are reconstructed by the filtered back projection algorithm. As the pixel size is 80 μm, the height of three-dimensional internal structure image of the straw is 6.48 mm. The presented system can rapidly reconstruct the three-dimensional object by using a pyroelectric array detector and explores the feasibility of on non-destructive evaluation and security testing.

  18. Determination of midsagittal plane for evaluation of facial asymmetry using three-dimensional computed tomography

    International Nuclear Information System (INIS)

    Kim, Tae Young; Huh, Kyung Hoe; Choi, Soon Chul; Baik, Jee Seon; Park, Joo Young; Chae, Hwa Sung

    2011-01-01

    The aim of the present study was to investigate the disagreement of cephalometric analysis depending on the reference determination of midsagittal plane on three-dimensional computed tomography. A total of 102 young women with class III dentofacial deformity were evaluated using three-dimensional computed tomography. The cranial and facial midsagittal planes were defined and the amounts of jaw deviation were calculated. The amounts of jaw deviation were compared with paired t-test (2-tailed) and Bland-Altman plot was drawn. The landmark tracing were reproducible (r≥.978). The jaws relative to the cranial midsagittal plane were 10-17 times more significantly deviated than to the facial midsagittal plane (P<.001). Bland-Altman plot demonstrated that the differences between the amounts of jaw deviation from two midsagittal planes were not normally distributed versus the average of the amounts of jaw deviation from two midsagittal planes. The cephalometric analyses of facial asymmetry were significantly inconsistent depending on the reference determination of midsagittal plane. The reference for midsagittal plane should be carefully determined in three-dimensional cephalometric analysis of facial asymmetry of patients with class III dentofacial deformity.

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

    Science.gov (United States)

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

    2014-06-01

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

  20. Three-dimensional digitizer (neuronavigator): new equipment for computed tomography-guided stereotaxic surgery.

    Science.gov (United States)

    Watanabe, E; Watanabe, T; Manaka, S; Mayanagi, Y; Takakura, K

    1987-06-01

    A new device was invented as an adjunct for computed tomography (CT)-guided stereotaxic or open neurosurgery. It is composed of a multijoint three-dimensional digitizer (sensor arm) and a microcomputer, which indicates the place of the sensor arm tip on preoperative CT images. Computed tomography scan is performed preoperatively with three markers placed on the nasion and ears. At surgery, after fixing the patient's head and the sensor arm, sampling of the standard points was done to translate the position of the tip of the sensor arm onto the CT images displayed on a computer screen. In this way positional data from conventional preoperative CT scan can be directly transferred into the surgical field. This system has the unique feature of introducing CT-guided stereotaxis into conventional open neurosurgery.

  1. Image reconstruction using three-dimensional compound Gauss-Markov random field in emission computed tomography

    International Nuclear Information System (INIS)

    Watanabe, Shuichi; Kudo, Hiroyuki; Saito, Tsuneo

    1993-01-01

    In this paper, we propose a new reconstruction algorithm based on MAP (maximum a posteriori probability) estimation principle for emission tomography. To improve noise suppression properties of the conventional ML-EM (maximum likelihood expectation maximization) algorithm, direct three-dimensional reconstruction that utilizes intensity correlations between adjacent transaxial slices is introduced. Moreover, to avoid oversmoothing of edges, a priori knowledge of RI (radioisotope) distribution is represented by using a doubly-stochastic image model called the compound Gauss-Markov random field. The a posteriori probability is maximized by using the iterative GEM (generalized EM) algorithm. Computer simulation results are shown to demonstrate validity of the proposed algorithm. (author)

  2. Three-dimensional assessment of unilateral subcondylar fracture using computed tomography after open reduction

    Directory of Open Access Journals (Sweden)

    Sathya Kumar Devireddy

    2014-01-01

    Full Text Available Objective: The aim was to assess the accuracy of three-dimensional anatomical reductions achieved by open method of treatment in cases of displaced unilateral mandibular subcondylar fractures using preoperative (pre op and postoperative (post op computed tomography (CT scans. Materials and Methods: In this prospective study, 10 patients with unilateral sub condylar fractures confirmed by an orthopantomogram were included. A pre op and post op CT after 1 week of surgical procedure was taken in axial, coronal and sagittal plane along with three-dimensional reconstruction. Standard anatomical parameters, which undergo changes due to fractures of the mandibular condyle were measured in pre and post op CT scans in three planes and statistically analysed for the accuracy of the reduction comparing the following variables: (a Pre op fractured and nonfractured side (b post op fractured and nonfractured side (c pre op fractured and post op fractured side. P < 0.05 was considered as significant. Results: Three-dimensional anatomical reduction was possible in 9 out of 10 cases (90%. The statistical analysis of each parameter in three variables revealed (P < 0.05 that there was a gross change in the dimensions of the parameters obtained in pre op fractured and nonfractured side. When these parameters were assessed in post op CT for the three variables there was no statistical difference between the post op fractured side and non fractured side. The same parameters were analysed for the three variables in pre op fractured and post op fractured side and found significant statistical difference suggesting a considerable change in the dimensions of the fractured side post operatively. Conclusion: The statistical and clinical results in our study emphasised that it is possible to fix the condyle in three-dimensional anatomical positions with open method of treatment and avoid post op degenerative joint changes. CT is the ideal imaging tool and should be used on

  3. Value of three-dimensional computed tomography in screening cerebral aneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Tamaki; Sugiura, Yusuke; Suzuki, Atsushi; Yamagata, Yoshitaka [Hyogo Medical Coll. (Japan)

    1997-10-01

    We performed three-dimensional computed tomography (3D-CT) in 6 patients of cerebral aneurysm. Prior cerebral angiography showed a total of 17 aneurysms. 3D-CT alone detected 10 cerebral aneurysm (59%). It was possible to identify aneurysms larger than 10 mm even when located near the circle of Willis. It was difficult to identify aneurysms when smaller than 7 mm regardless of their location. 3D-CT was of limited value in detecting cerebral aneurysms, particularly when located near the circle of Willis with complex vascular network. As cases of oculomotor palsy may be caused by lesions other than cerebral aneurysm, we advocate that 3D-CT be performed after magnetic resonance imaging (MRI) in screening cases of suspected cerebral aneurysm. (author)

  4. Three-Dimensional Computed Tomography as a Method for Finding Die Attach Voids in Diodes

    Science.gov (United States)

    Brahm, E. N.; Rolin, T. D.

    2010-01-01

    NASA analyzes electrical, electronic, and electromechanical (EEE) parts used in space vehicles to understand failure modes of these components. The diode is an EEE part critical to NASA missions that can fail due to excessive voiding in the die attach. Metallography, one established method for studying the die attach, is a time-intensive, destructive, and equivocal process whereby mechanical grinding of the diodes is performed to reveal voiding in the die attach. Problems such as die attach pull-out tend to complicate results and can lead to erroneous conclusions. The objective of this study is to determine if three-dimensional computed tomography (3DCT), a nondestructive technique, is a viable alternative to metallography for detecting die attach voiding. The die attach voiding in two- dimensional planes created from 3DCT scans was compared to several physical cross sections of the same diode to determine if the 3DCT scan accurately recreates die attach volumetric variability

  5. Optical computed tomography in PRESAGE® three-dimensional dosimetry: Challenges and prospective.

    Science.gov (United States)

    Khezerloo, Davood; Nedaie, Hassan Ali; Farhood, Bagher; Zirak, Alireza; Takavar, Abbas; Banaee, Nooshin; Ahmadalidokht, Isa; Kron, Tomas

    2017-01-01

    With the advent of new complex but precise radiotherapy techniques, the demands for an accurate, feasible three-dimensional (3D) dosimetry system have been increased. A 3D dosimeter system generally should not only have accurate and precise results but should also feasible, inexpensive, and time consuming. Recently, one of the new candidates for 3D dosimetry is optical computed tomography (CT) with a radiochromic dosimeter such as PRESAGE®. Several generations of optical CT have been developed since the 90s. At the same time, a large attempt has been also done to introduce the robust dosimeters that compatible with optical CT scanners. In 2004, PRESAGE® dosimeter as a new radiochromic solid plastic dosimeters was introduced. In this decade, a large number of efforts have been carried out to enhance optical scanning methods. This article attempts to review and reflect on the results of these investigations.

  6. Optical computed tomography in PRESAGE® three-dimensional dosimetry: Challenges and prospective

    Directory of Open Access Journals (Sweden)

    Davood Khezerloo

    2017-01-01

    Full Text Available With the advent of new complex but precise radiotherapy techniques, the demands for an accurate, feasible three-dimensional (3D dosimetry system have been increased. A 3D dosimeter system generally should not only have accurate and precise results but should also feasible, inexpensive, and time consuming. Recently, one of the new candidates for 3D dosimetry is optical computed tomography (CT with a radiochromic dosimeter such as PRESAGE®. Several generations of optical CT have been developed since the 90s. At the same time, a large attempt has been also done to introduce the robust dosimeters that compatible with optical CT scanners. In 2004, PRESAGE® dosimeter as a new radiochromic solid plastic dosimeters was introduced. In this decade, a large number of efforts have been carried out to enhance optical scanning methods. This article attempts to review and reflect on the results of these investigations.

  7. 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.

  8. Three-dimensional computed tomography analysis of non-osteoarthritic adult acetabular dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi; Matsuno, Takeo; Hirayama, Teruhisa; Tanino, Hiromasa; Yamanaka, Yasuhiro [Asahikawa Medical College, Department of Orthopaedic Surgery, Asahikawa (Japan); Minami, Akio [Hokkaido University School of Medicine, Department of Orthopaedic Surgery, Sapporo (Japan)

    2009-02-15

    Little data exists on the original morphology of acetabular dysplasia obtained from patients without radiographic advanced osteoarthritic changes. The aim of this study was to investigate the distribution and degree of acetabular dysplasia in a large number of patients showing no advanced degenerative changes using three-dimensional computed tomography (3DCT). Eighty-four dysplastic hips in 55 consecutive patients were studied. All 84 hips were in pre- or early osteoarthritis without radiographic evidence of joint space narrowing, formation of osteophytes or cysts, or deformity of femoral heads. The mean age at the time of CT scan was 35 years (range 15-64 years). 3D images were reconstructed and analyzed using recent computer imaging software (INTAGE Realia and Volume Player). Deficiency types and degrees of acetabular dysplasia were precisely evaluated using these computer software. The average Harris hip score at CT scans was 82 points. Twenty-two hips (26%) were classified as anterior deficiency, 17 hips (20%) as posterior deficiency, and 45 hips (54%) as lateral deficiency. No significant difference was found in the Harris hip score among these groups. The analysis of various measurements indicated wide variations. There was a significant correlation between the Harris hip score and the acetabular coverage (p < 0.001). Our results indicated wide variety of deficiency type and degree of acetabular dysplasia. Hips with greater acetabular coverage tended to have a higher Harris hip score. (orig.)

  9. Three-dimensional computed tomography analysis of non-osteoarthritic adult acetabular dysplasia

    International Nuclear Information System (INIS)

    Ito, Hiroshi; Matsuno, Takeo; Hirayama, Teruhisa; Tanino, Hiromasa; Yamanaka, Yasuhiro; Minami, Akio

    2009-01-01

    Little data exists on the original morphology of acetabular dysplasia obtained from patients without radiographic advanced osteoarthritic changes. The aim of this study was to investigate the distribution and degree of acetabular dysplasia in a large number of patients showing no advanced degenerative changes using three-dimensional computed tomography (3DCT). Eighty-four dysplastic hips in 55 consecutive patients were studied. All 84 hips were in pre- or early osteoarthritis without radiographic evidence of joint space narrowing, formation of osteophytes or cysts, or deformity of femoral heads. The mean age at the time of CT scan was 35 years (range 15-64 years). 3D images were reconstructed and analyzed using recent computer imaging software (INTAGE Realia and Volume Player). Deficiency types and degrees of acetabular dysplasia were precisely evaluated using these computer software. The average Harris hip score at CT scans was 82 points. Twenty-two hips (26%) were classified as anterior deficiency, 17 hips (20%) as posterior deficiency, and 45 hips (54%) as lateral deficiency. No significant difference was found in the Harris hip score among these groups. The analysis of various measurements indicated wide variations. There was a significant correlation between the Harris hip score and the acetabular coverage (p < 0.001). Our results indicated wide variety of deficiency type and degree of acetabular dysplasia. Hips with greater acetabular coverage tended to have a higher Harris hip score. (orig.)

  10. Three dimensional morphological studies of Larger Benthic Foraminifera at the population level using micro computed tomography

    Science.gov (United States)

    Kinoshita, Shunichi; Eder, Wolfgang; Woeger, Julia; Hohenegger, Johann; Briguglio, Antonino; Ferrandez-Canadell, Carles

    2015-04-01

    Symbiont-bearing larger benthic Foraminifera (LBF) are long-living marine (at least 1 year), single-celled organisms with complex calcium carbonate shells. Their morphology has been intensively studied since the middle of the nineteenth century. This led to a broad spectrum of taxonomic results, important from biostratigraphy to ecology in shallow water tropical to warm temperate marine palaeo-environments. However, it was necessary for the traditional investigation methods to cut or destruct specimens for analysing the taxonomically important inner structures. X-ray micro-computed tomography (microCT) is one of the newest techniques used in morphological studies. The greatest advantage is the non-destructive acquisition of inner structures. Furthermore, the running improve of microCT scanners' hard- and software provides high resolution and short time scans well-suited for LBF. Three-dimensional imaging techniques allow to select and extract each chamber and to measure easily its volume, surface and several form parameters used for morphometric analyses. Thus, 3-dimensional visualisation of LBF-tests is a very big step forward from traditional morphology based on 2-dimensional data. The quantification of chamber form is a great opportunity to tackle LBF structures, architectures and the bauplan geometry. The micrometric digital resolution is the only way to solve many controversies in phylogeny and evolutionary trends of LBF. For the present study we used micro-computed tomography to easily investigate the chamber number of every specimen from statistically representative part of populations to estimate population dynamics. Samples of living individuals are collected at monthly intervals from fixed locations. Specific preparation allows to scan up to 35 specimens per scan within 2 hours and to obtain the complete digital dataset for each specimen of the population. MicroCT enables thus a fast and precise count of all chambers built by the foraminifer from its

  11. Clinical application of electron beam computed tomography in intravenous three-dimensional coronary angiography

    International Nuclear Information System (INIS)

    Luo Chufan; Du Zhimin; Hu Chengheng; Li Yi; Zeng Wutao; Ma Hong; Li Xiangmin; Zhou Xuhui

    2002-01-01

    Objective: To investigate the clinical application of intravenous three-dimensional coronary angiography using electron beam computed tomography (EBCT) as compared with selective coronary angiography. Methods: Intravenous EBCT and selective coronary angiography were performed during the same period in 38 patients. The value of EBCT angiography for diagnosing coronary artery disease was evaluated. Results: The number of coronary arteries adequately evaluated by EBCT angiography was 134 out of 152 vessels (88.2%), including 100% of the left main coronary arteries, 94.7% of the left anterior descending arteries, 81.6% of the left circumflex arteries and 76.3 % of the right coronary arteries. Significantly more left main and heft anterior descending coronary arteries were adequately visualized than the left circumflex and right coronary arteries (P < 0.05). The sensitivity, specificity, accuracy, and positive and negative predictive value of EBCT angiography for diagnosing coronary artery disease were 88.0%, 84.6%, 86.8%, 91.7% and 78.6%, respectively. Of the 38 arteries with ≥ 50% stenosis, EBCT underestimated 8, for a sensitivity of 78.9%. Of the 96 arteries without significant stenosis, EBCT overestimated 7 stenosis, for a specificity of 92.7%. Conclusion: Intravenous electron beam computed tomographic coronary angiography is a promising noninvasive method for diagnosing coronary artery disease

  12. Examination of craniofacial bones associated with auricular anomaly using three-dimensional computer tomography

    International Nuclear Information System (INIS)

    Ono, Ichiro; Ohura, Takehiko; Iwao, Fumiya

    1989-01-01

    Three-dimensional computer tomography (3D-CT) was performed in 60 patients with auricular anomaly to determine the site and severity of deformity in the hemifacial microsomia. Auricular anomaly, underdevelopment and malposition of the cranium, temporo-mandibular joint, zygoma, maxilla and mandible were observed in almost all of the patients; however, the severity of these malformations varied from patient to patient. Regarding severest deformity, there were positional differences among patients. According to impairment sites, hemifacial microsomia fell into the following five types: (1) cranium type, (2) maxillary alveolar process type, (3) localized mandibular ramus type, (4) overall mandibular type, and (5) complex type (combination of the aforementioned types). Facial asymmetry accompanied by auricular anomaly was associated with various pathologic conditions. The temporomandibular joint was often deviated towards the anteromedial side for localized mandibular ramus type and overall mandibular type. Posterial deviation was predominant for cranium type. In patients with hemifacial microsomia of the cranium type associated with protrusion mainly in the occipital region on the affected side, deformity was considered attributable to underdevelopment of the temporal bone and delay in closure of the temporo-occipital suture. The deformity for cranium type may be defined as the second branchial syndrome. In conclusion, hemifacial microsomia have various deformities and may fall into five categories. Craniofacial microsomia and hemi-auriculo-temporo-mandibular dysplastic syndrome give a more precise concept for auricular anomaly. (N.K.)

  13. Examination of craniofacial bones associated with auricular anomaly using three-dimensional computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Ichiro; Ohura, Takehiko; Iwao, Fumiya (Hokkaido Univ., Sapporo (Japan). School of Medicine) (and others)

    1989-07-01

    Three-dimensional computer tomography (3D-CT) was performed in 60 patients with auricular anomaly to determine the site and severity of deformity in the hemifacial microsomia. Auricular anomaly, underdevelopment and malposition of the cranium, temporo-mandibular joint, zygoma, maxilla and mandible were observed in almost all of the patients; however, the severity of these malformations varied from patient to patient. Regarding severest deformity, there were positional differences among patients. According to impairment sites, hemifacial microsomia fell into the following five types: (1) cranium type, (2) maxillary alveolar process type, (3) localized mandibular ramus type, (4) overall mandibular type, and (5) complex type (combination of the aforementioned types). Facial asymmetry accompanied by auricular anomaly was associated with various pathologic conditions. The temporomandibular joint was often deviated towards the anteromedial side for localized mandibular ramus type and overall mandibular type. Posterial deviation was predominant for cranium type. In patients with hemifacial microsomia of the cranium type associated with protrusion mainly in the occipital region on the affected side, deformity was considered attributable to underdevelopment of the temporal bone and delay in closure of the temporo-occipital suture. The deformity for cranium type may be defined as the second branchial syndrome. In conclusion, hemifacial microsomia have various deformities and may fall into five categories. Craniofacial microsomia and hemi-auriculo-temporo-mandibular dysplastic syndrome give a more precise concept for auricular anomaly. (N.K.).

  14. Three dimensional computed tomography lung modeling is useful in simulation and navigation of lung cancer surgery.

    Science.gov (United States)

    Ikeda, Norihiko; Yoshimura, Akinobu; Hagiwara, Masaru; Akata, Soichi; Saji, Hisashi

    2013-01-01

    The number of minimally invasive operations, such as video-assisted thoracoscopic surgery (VATS) lobectomy or segmentectomy, has enormously increased in recent years. These operations require extreme knowledge of the anatomy of pulmonary vessels and bronchi in each patient, and surgeons must carefully dissect the branches of pulmonary vessels during operation. Thus, foreknowledge of the anatomy of each patient would greatly contribute to the safety and accuracy of the operation. The development of multi-detector computed tomography (MDCT) has promoted three dimensional (3D) images of lung structures. It is possible to see the vascular and bronchial structures from the view of the operator; therefore, it is employed for preoperative simulation as well as navigation during operation. Due to advances in software, even small vessels can be accurately imaged, which is useful in performing segmentectomy. Surgical simulation and navigation systems based on high quality 3D lung modeling, including vascular and bronchial structures, can be used routinely to enhance the safety operation, education of junior staff, as well as providing a greater sense of security to the operators.

  15. Enlargement of lumbar spinal canal in lumbar degenerative spondylolisthesis. Evaluation with three-dimensional computed tomography

    International Nuclear Information System (INIS)

    Kunishi, Yoshihiko

    2003-01-01

    A number of clinical studies have demonstrated that enlargement of the lumbar spinal canal is one of the effective surgical procedures for the treatment of the lumbar degenerative spondylolisthesis and provides a good result. In the present study, we have evaluated the long-term outcome of the enlargement of the lumbar canal without fusion in thirty eight patients with lumbar degenerative spondylolisthesis using three-dimensional computed tomography (3D-CT) The improvement rate was excellent in 80% of the patients (mean improvement ratio, 83%) according to the Japanese Orthopedic Association scoring system. We found that the sufficient enlargement of the canal was obtained by the surgery and maintained for a long period of time. The results from 3D-CT suggested that a round shape was maintained in the canal after the surgery because of pressures of the dura mater against to the bony canal. None of patients showed lumbar instability. In conclusion, enlargement of lumbar canal without fusion is useful for the treatment of lumbar degenerative spondylolisthesis, and the enlarged canal has been maintained for a long period of time after the surgery. The results demonstrated the clinical utility of 3D-CT to evaluate the preoperative and postoperative shape of the spine. (author)

  16. Three-dimensional computed tomography reconstruction for operative planning in robotic segmentectomy: a pilot study.

    Science.gov (United States)

    Le Moal, Julien; Peillon, Christophe; Dacher, Jean-Nicolas; Baste, Jean-Marc

    2018-01-01

    The objective of our pilot study was to assess if three-dimensional (3D) reconstruction performed by Visible Patient™ could be helpful for the operative planning, efficiency and safety of robot-assisted segmentectomy. Between 2014 and 2015, 3D reconstructions were provided by the Visible Patient™ online service and used for the operative planning of robotic segmentectomy. To obtain 3D reconstruction, the surgeon uploaded the anonymized computed tomography (CT) image of the patient to the secured Visible Patient™ server and then downloaded the model after completion. Nine segmentectomies were performed between 2014 and 2015 using a pre-operative 3D model. All 3D reconstructions met our expectations: anatomical accuracy (bronchi, arteries, veins, tumor, and the thoracic wall with intercostal spaces), accurate delimitation of each segment in the lobe of interest, margin resection, free space rotation, portability (smartphone, tablet) and time saving technique. We have shown that operative planning by 3D CT using Visible Patient™ reconstruction is useful in our practice of robot-assisted segmentectomy. The main disadvantage is the high cost. Its impact on reducing complications and improving surgical efficiency is the object of an ongoing study.

  17. Three Dimensional Digital Sieving of Asphalt Mixture Based on X-ray Computed Tomography

    Directory of Open Access Journals (Sweden)

    Chichun Hu

    2017-07-01

    Full Text Available In order to perform three-dimensional digital sieving based on X-ray computed tomography images, the definition of digital sieve size (DSS was proposed, which was defined as the minimum length of the minimum bounding squares of all possible orthographic projections of an aggregate. The corresponding program was developed to reconstruct aggregate structure and to obtain DSS. Laboratory experiments consisting of epoxy-filled aggregate specimens were conducted to investigate the difference between mechanical sieve analysis and the digital sieving technique. It was suggested that concave surface of aggregate was the possible reason for the disparity between DSS and mechanical sieve size. A comparison between DSS and equivalent diameter was also performed. Moreover, the digital sieving technique was adopted to evaluate the gradation of stone mastic asphalt mixtures. The results showed that the closest proximity of the laboratory gradation curve was achieved by calibrated DSS, among gradation curves based on calibrated DSS, un-calibrated DSS and equivalent diameter.

  18. Radiologic study of mandibular foramen of mandibular prognathism by three-dimensional computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hun; Moon, Cheol Hyun; Im, Jeong Soo; Seo, Hwa Jeong [Graduate School of Public Health and Social Welfare, Gachon University of Medicine and Science, Incheon (Korea, Republic of)

    2010-06-15

    This study is aimed to evaluate the position of mandibular foramen of mandibular prognathism patients using 3-dimensional CT images in order to reduce the chance of an anesthetic failure of the mandibular nerve and to prevent the damage to the inferior alveolar nerve during the orthognathic surgery. The control group consist of 30 patients with class I occlusion. The experimental group consist of 44 patients with class III malocclusion. Three-dimensional computed tomography was used to evaluate the position of the mandibular foramina. The distance between mandibular plane and mandibular foramen, class I was 25.385 mm, class III was 23.628 mm. About the distance between occlusal plane and mandibular foramen, class I was 1.478 mm, class III was 5.144 mm. The distance between posterior border plan of mandibular ramus and mandibular foramen had not statistically significant. About the distance between sagittal plane of mandible and mandibular foramen did not also showed statistically significant. The result of this study could help the clinicians to apprehend more accurate anatomical locations of the foramina on the mandible with various facial skeletal types. Thereby to perform more accurate block anesthesia of the mandibular nerve and osteotomy with minimal nerve damage. In addition, this study could provide fundamental data for any related researches about the location of the mandibular foramina for other purposes.

  19. Radiologic study of mandibular foramen of mandibular prognathism by three-dimensional computed tomography

    International Nuclear Information System (INIS)

    Lee, Seung Hun; Moon, Cheol Hyun; Im, Jeong Soo; Seo, Hwa Jeong

    2010-01-01

    This study is aimed to evaluate the position of mandibular foramen of mandibular prognathism patients using 3-dimensional CT images in order to reduce the chance of an anesthetic failure of the mandibular nerve and to prevent the damage to the inferior alveolar nerve during the orthognathic surgery. The control group consist of 30 patients with class I occlusion. The experimental group consist of 44 patients with class III malocclusion. Three-dimensional computed tomography was used to evaluate the position of the mandibular foramina. The distance between mandibular plane and mandibular foramen, class I was 25.385 mm, class III was 23.628 mm. About the distance between occlusal plane and mandibular foramen, class I was 1.478 mm, class III was 5.144 mm. The distance between posterior border plan of mandibular ramus and mandibular foramen had not statistically significant. About the distance between sagittal plane of mandible and mandibular foramen did not also showed statistically significant. The result of this study could help the clinicians to apprehend more accurate anatomical locations of the foramina on the mandible with various facial skeletal types. Thereby to perform more accurate block anesthesia of the mandibular nerve and osteotomy with minimal nerve damage. In addition, this study could provide fundamental data for any related researches about the location of the mandibular foramina for other purposes.

  20. Recent advances in Optical Computed Tomography (OCT) imaging system for three dimensional (3D) radiotherapy dosimetry

    Science.gov (United States)

    Rahman, Ahmad Taufek Abdul; Farah Rosli, Nurul; Zain, Shafirah Mohd; Zin, Hafiz M.

    2018-01-01

    Radiotherapy delivery techniques for cancer treatment are becoming more complex and highly focused, to enable accurate radiation dose delivery to the cancerous tissue and minimum dose to the healthy tissue adjacent to tumour. Instrument to verify the complex dose delivery in radiotherapy such as optical computed tomography (OCT) measures the dose from a three-dimensional (3D) radiochromic dosimeter to ensure the accuracy of the radiotherapy beam delivery to the patient. OCT measures the optical density in radiochromic material that changes predictably upon exposure to radiotherapy beams. OCT systems have been developed using a photodiode and charged coupled device (CCD) as the detector. The existing OCT imaging systems have limitation in terms of the accuracy and the speed of the measurement. Advances in on-pixel intelligence CMOS image sensor (CIS) will be exploited in this work to replace current detector in OCT imaging systems. CIS is capable of on-pixel signal processing at a very fast imaging speed (over several hundred images per second) that will allow improvement in the 3D measurement of the optical density. The paper will review 3D radiochromic dosimeters and OCT systems developed and discuss how CMOS based OCT imaging will provide accurate and fast optical density measurements in 3D. The paper will also discuss the configuration of the CMOS based OCT developed in this work and how it may improve the existing OCT system.

  1. Three-dimensional maximum principal strain using cardiac computed tomography for identification of myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Yuki; Kido, Teruhito; Kurata, Akira; Sawada, Shun; Suekuni, Hiroshi; Kido, Tomoyuki; Yokoi, Takahiro; Miyagawa, Masao; Mochizuki, Teruhito [Ehime University Graduate School of Medicine, Department of Radiology, Toon City, Ehime (Japan); Uetani, Teruyoshi; Inoue, Katsuji [Ehime University Graduate School of Medicine, Department of Cardiology, Pulmonology, Hypertension and Nephrology, Toon City, Ehime (Japan)

    2017-04-15

    To evaluate the feasibility of three-dimensional (3D) maximum principal strain (MP-strain) derived from cardiac computed tomography (CT) for detecting myocardial infarction (MI). Forty-three patients who underwent cardiac CT and magnetic resonance imaging (MRI) were retrospectively selected. Using the voxel tracking of motion coherence algorithm, the peak CT MP-strain was measured using the 16-segment model. With the trans-mural extent of late gadolinium enhancement (LGE) and the distance from MI, all segments were classified into four groups (infarcted, border, adjacent, and remote segments); infarcted and border segments were defined as MI with LGE positive. Diagnostic performance of MP-strain for detecting MI was compared with per cent systolic wall thickening (%SWT) assessed by MRI using receiver-operating characteristic curve analysis at a segment level. Of 672 segments excluding16 segments influenced by artefacts, 193 were diagnosed as MI. Sensitivity and specificity of peak MP-strain to identify MI were 81 % [95 % confidence interval (95 % CI): 74-88 %] and 86 % (81-92 %) compared with %SWT: 76 % (60-95 %) and 68 % (48-84 %), respectively. The area under the curve of peak MP-strain was superior to %SWT [0.90 (0.87-0.93) vs. 0.80 (0.76-0.83), p < 0.05]. CT MP-strain has a potential to provide incremental value to coronary CT angiography for detecting MI. (orig.)

  2. Cochlear implant-related three-dimensional characteristics determined by micro-computed tomography reconstruction.

    Science.gov (United States)

    Ni, Yusu; Dai, Peidong; Dai, Chunfu; Li, Huawei

    2017-01-01

    To explore the structural characteristics of the cochlea in three-dimensional (3D) detail using 3D micro-computed tomography (mCT) image reconstruction of the osseous labyrinth, with the aim of improving the structural design of electrodes, the selection of stimulation sites, and the effectiveness of cochlear implantation. Three temporal bones were selected from among adult donors' temporal bone specimens. A micro-CT apparatus (GE eXplore) was used to scan three specimens with a voxel resolution of 45 μm. We obtained about 460 slices/specimen, which produced abundant data. The osseous labyrinth images of three specimens were reconstructed from mCT. The cochlea and its spiral characteristics were measured precisely using Able Software 3D-DOCTOR. The 3D images of the osseous labyrinth, including the cochlea, vestibule, and semicircular canals, were reconstructed. The 3D models of the cochlea showed the spatial relationships and surface structural characteristics. Quantitative data concerning the cochlea and its spiral structural characteristics were analyzed with regard to cochlear implantation. The 3D reconstruction of mCT images clearly displayed the detailed spiral structural characteristics of the osseous labyrinth. Quantitative data regarding the cochlea and its spiral structural characteristics could help to improve electrode structural design, signal processing, and the effectiveness of cochlear implantation. Clin. Anat. 30:39-43, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Bilateral and pseudobilateral tonsilloliths: Three dimensional imaging with cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Misirlioglu, Melda; Adisen, Mehmet Zahit; Yardimci, Selmi [Dept. of Oral and Maxillofacial Radiology, Faculty of Dentistry, Kirikkale University, Kirikkale (Turkmenistan); Nalcaci, Rana [Dept. of Oral and Maxillofacial Radiology, Faculty of Dentistry, Ankara University, Ankara (Turkmenistan)

    2013-09-15

    Tonsilloliths are calcifications found in the crypts of the palatal tonsils and can be detected on routine panoramic examinations. This study was performed to highlight the benefits of cone-beam computed tomography (CBCT) in the diagnosis of tonsilloliths appearing bilaterally on panoramic radiographs. The sample group consisted of 7 patients who had bilateral radiopaque lesions at the area of the ascending ramus on panoramic radiographs. CBCT images for every patient were obtained from both sides of the jaw to determine the exact locations of the lesions and to rule out other calcifications. The calcifications were evaluated on the CBCT images using Ez3D2009 software. Additionally, the obtained images in DICOM format were transferred to ITK SNAP 2.4.0 pc software for semiautomatic segmentation. Segmentation was performed using contrast differences between the soft tissues and calcifications on grayscale images, and the volume in mm{sup 3} of the segmented three dimensional models were obtained. CBCT scans revealed that what appeared on panoramic radiographs as bilateral images were in fact unilateral lesions in 2 cases. The total volume of the calcifications ranged from 7.92 to 302.5mm{sup 3}. The patients with bilaterally multiple and large calcifications were found to be symptomatic. The cases provided the evidence that tonsilloliths should be considered in the differential diagnosis of radiopaque masses involving the mandibular ramus, and they highlight the need for a CBCT scan to differentiate pseudo- or ghost images from true bilateral pathologies.

  4. Three-dimensional computed tomography in the assessment of congenital scoliosis

    International Nuclear Information System (INIS)

    Bush, C.H.; Kalen, V.

    1999-01-01

    Objective. Patients with congenital vertebral anomalies frequently are afflicted with kyphoscoliosis, with the curvatures often being severe and progressive. Spinal fusion almost always is the treatment of choice in such patients. This report examines the use of three-dimensional computed tomography (3D CT) in the preoperative investigation of patients with congenital scoliosis.Design and patients. Twelve spinal CT examinations on 11 pediatric patients with congenital scoliosis underwent image processing to produce 3D images. The 3D images were compared with both the axial sections from the CT examinations and multiplanar reformations with regard to the detection of malformations liable to cause progression of scoliosis (i. e., hemivertebrae and unsegmented bars).Results and conclusions. In six of the 12 cases, the 3D images provided improved depiction of the congenital anomalies and their interrelationships compared with planar CT images. This work suggests that 3D CT can be a useful tool in the assessment of patients with congenital scoliosis. (orig.)

  5. Three-Dimensional Printing of X-Ray Computed Tomography Datasets with Multiple Materials Using Open-Source Data Processing

    Science.gov (United States)

    Sander, Ian M.; McGoldrick, Matthew T.; Helms, My N.; Betts, Aislinn; van Avermaete, Anthony; Owers, Elizabeth; Doney, Evan; Liepert, Taimi; Niebur, Glen; Liepert, Douglas; Leevy, W. Matthew

    2017-01-01

    Advances in three-dimensional (3D) printing allow for digital files to be turned into a "printed" physical product. For example, complex anatomical models derived from clinical or pre-clinical X-ray computed tomography (CT) data of patients or research specimens can be constructed using various printable materials. Although 3D printing…

  6. Comparative study of cranial anthropometric measurement by traditional calipers to computed tomography and three-dimensional photogrammetry.

    Science.gov (United States)

    Mendonca, Derick A; Naidoo, Sybill D; Skolnick, Gary; Skladman, Rachel; Woo, Albert S

    2013-07-01

    Craniofacial anthropometry by direct caliper measurements is a common method of quantifying the morphology of the cranial vault. New digital imaging modalities including computed tomography and three-dimensional photogrammetry are similarly being used to obtain craniofacial surface measurements. This study sought to compare the accuracy of anthropometric measurements obtained by calipers versus 2 methods of digital imaging.Standard anterior-posterior, biparietal, and cranial index measurements were directly obtained on 19 participants with an age range of 1 to 20 months. Computed tomographic scans and three-dimensional photographs were both obtained on each child within 2 weeks of the clinical examination. Two analysts measured the anterior-posterior and biparietal distances on the digital images. Measures of reliability and bias between the modalities were calculated and compared.Caliper measurements were found to underestimate the anterior-posterior and biparietal distances as compared with those of the computed tomography and the three-dimensional photogrammetry (P photogrammetry (P = 0.002). The coefficients of variation for repeated measures based on the computed tomography and the three-dimensional photogrammetry were 0.008 and 0.007, respectively.In conclusion, measurements based on digital modalities are generally reliable and interchangeable. Caliper measurements lead to underestimation of anterior-posterior and biparietal values compared with digital imaging.

  7. Prenatal diagnosis of sirenomelia in the late second trimester with three-dimensional helical computed tomography.

    Science.gov (United States)

    Ono, Tetsuo; Katsura, Daisuke; Tsuji, Shunichiro; Yomo, Hiroko; Ishiko, Akiko; Inoue, Takashi; Kita, Nobuyuki; Takahashi, Kentaro; Murakami, Takashi

    2011-10-01

    Sirenomelia is a rare congenital syndrome that is characterized by the anomalous development of the caudal region of the body. The anomalies include bilateral renal agenesis or dysgenesis and the absence of the sacrum and other vertebral defects. Sirenomelia is also known as "mermaid syndrome," because of the one lower extremity. It is usually associated with severe oligohydramnios, and its prognosis is very poor due to pulmonary hypoplasia that is caused by severe oligohydramnios. The patient referred to our hospital at the gestational age of 27 weeks with fetal growth restriction and oligohydramnios. The estimated fetal body weight was 970 g (-4.9 S.D.). We could identify only one-side extremities, and could not identify kidneys by ultrasound examination. Because a single lower extremity and severe oligohydramnios are characteristics of the sirenomelia, we suspected sirenomelia. However, it could not be confirmed by ultrasound examination because of oligohydramnios. Therefore, we performed three-dimensional helical computed tomography (3D-CT), which is more accurate than ultrasound examinations for prenatal diagnosis of skeletal abnormalities. 3D-CT revealed an only one lower extremity. At 36 weeks and 5 days of gestation, the woman went into spontaneous labor and delivered an infant weighing 870 g. The infant has a single upper extremity and a single lower extremity. We provided supportive care for the neonate, who however died 1 hour 36 minutes after birth from severe respiratory distress. In summary, we report the correct diagnosis of sirenomelia with 3D-CT in the late second trimester.

  8. Enabling three-dimensional densitometric measurements using laboratory source X-ray micro-computed tomography

    Science.gov (United States)

    Pankhurst, M. J.; Fowler, R.; Courtois, L.; Nonni, S.; Zuddas, F.; Atwood, R. C.; Davis, G. R.; Lee, P. D.

    2018-01-01

    We present new software allowing significantly improved quantitative mapping of the three-dimensional density distribution of objects using laboratory source polychromatic X-rays via a beam characterisation approach (c.f. filtering or comparison to phantoms). One key advantage is that a precise representation of the specimen material is not required. The method exploits well-established, widely available, non-destructive and increasingly accessible laboratory-source X-ray tomography. Beam characterisation is performed in two stages: (1) projection data are collected through a range of known materials utilising a novel hardware design integrated into the rotation stage; and (2) a Python code optimises a spectral response model of the system. We provide hardware designs for use with a rotation stage able to be tilted, yet the concept is easily adaptable to virtually any laboratory system and sample, and implicitly corrects the image artefact known as beam hardening.

  9. Three-dimensional biplanar radiography as a new means of accessing femoral version: a comparitive study of EOS three-dimensional radiography versus computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Pomerantz, M.L. [University of California San Diego School of Medicine, Orthopaedic Surgery Department, San Diego, CA (United States); Glaser, Diana [Aurora Spine, Carlsbad, CA (United States); Doan, Josh [Orthopedic Biomechanics Research Center, San Diego, CA (United States); Kumar, Sita [University of California, San Diego, CA (United States); Edmonds, Eric W. [University of California San Diego School of Medicine, Orthopaedic Surgery Department, San Diego, CA (United States); Rady Children' s Hospital San Diego, Division of Orthopedic Surgery, San Diego, CA (United States)

    2014-10-17

    To validate femoral version measurements made from biplanar radiography (BR), three-dimensional (3D) reconstructions (EOS imaging, France) were made in differing rotational positions against the gold standard of computed tomography (CT). Two cadaveric femurs were scanned with CT and BR in five different femoral versions creating ten total phantoms. The native version was modified by rotating through a mid-diaphyseal hinge twice into increasing anteversion and twice into increased retroversion. For each biplanar scan, the phantom itself was rotated -10, -5, 0, +5 and +10 . Three-dimensional CT reconstructions were designated the true value for femoral version. Two independent observers measured the femoral version on CT axial slices and BR 3D reconstructions twice. The mean error (upper bound of the 95 % confidence interval), inter- and intraobserver reliability, and the error compared to the true version were determined for both imaging techniques. Interobserver intraclass correlation for CT axial images ranged from 0.981 to 0.991, and the intraobserver intraclass correlation ranged from 0.994 to 0.996. For the BR 3D reconstructions these values ranged from 0.983 to 0.998 and 0.982 to 0.998, respectively. For the CT measurements the upper bound of error from the true value was 5.4-7.5 , whereas for BR 3D reconstructions it was 4.0-10.1 . There was no statistical difference in the mean error from the true values for any of the measurements done with axial CT or BR 3D reconstructions. BR 3D reconstructions accurately and reliably provide clinical data on femoral version compared to CT even with rotation of the patient of up to 10 from neutral. (orig.)

  10. Three dimensional field computation

    International Nuclear Information System (INIS)

    Trowbridge, C.W.

    1981-06-01

    Recent research work carried out at Rutherford and Appleton Laboratories into the Computation of Electromagnetic Fields is summarised. The topics covered include algorithms for integral and differential methods for the solution of 3D magnetostatic fields, comparison of results with experiment and an investigation into the strengths and weaknesses of both methods for an analytic problem. The paper concludes with a brief summary of the work in progress on the solution of 3D eddy currents using differential finite elements. (author)

  11. Interobserver reliability of coronoid fracture classification: two-dimensional versus three-dimensional computed tomography

    NARCIS (Netherlands)

    Lindenhovius, Anneluuk; Karanicolas, Paul Jack; Bhandari, Mohit; van Dijk, Niek; Ring, David; Allan, Christopher; Anglen, Jeffrey; Axelrod, Terry; Baratz, Mark; Beingessner, Daphne; Brink, Peter; Cassidy, Charles; Coles, Chad; Conflitti, Joe; Crist, Brett; Della Rocca, Gregory; Dijkstra, Sander; Elmans, L. H. G. J.; Feibel, Roger; Flores, Luis; Frihagen, Frede; Gosens, Taco; Goslings, J. C.; Greenberg, Jeffrey; Grosso, Elena; Harness, Neil; van der Heide, Huub; Jeray, Kyle; Kalainov, David; van Kampen, Albert; Kawamura, Sumito; Kloen, Peter; McKee, Michael; Nork, Sean; Page, Richard; Pesantez, Rodrigo; Peters, Anil; Poolman, Rudolf; Prayson, Michael; Richardson, Martin; Seiler, John; Swiontkowski, Marc; Thomas, George; Trumble, Tom; van Vugt, Arie; Wright, Thomas; Zalavras, Charalampos; Zura, Robert

    2009-01-01

    This study tests the hypothesis that 3-dimensional computed tomography (CT) reconstructions improve interobserver agreement on classification and treatment of coronoid fractures compared with 2-dimensional CT. A total of 29 orthopedic surgeons evaluated 10 coronoid fractures on 2 occasions (first

  12. 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.

  13. Measurement of cardiac ventricular volumes using multidetector row computed tomography: comparison of two- and three-dimensional methods

    International Nuclear Information System (INIS)

    Montaudon, M.; Laffon, E.; Berger, P.; Corneloup, O.; Latrabe, V.; Laurent, F.

    2006-01-01

    This study compared a three-dimensional volumetric threshold-based method to a two-dimensional Simpson's rule based short-axis multiplanar method for measuring right (RV) and left ventricular (LV) volumes, stroke volumes, and ejection fraction using electrocardiography-gated multidetector computed tomography (MDCT) data sets. End-diastolic volume (EDV) and end-systolic volume (ESV) of RV and LV were measured independently and blindly by two observers from contrast-enhanced MDCT images using commercial software in 18 patients. For RV and LV the three-dimensionally calculated EDV and ESV values were smaller than those provided by two-dimensional short axis (10%, 5%, 15% and 26% differences respectively). Agreement between the two methods was found for LV (EDV/ESV: r=0.974/0.910, ICC=0.905/0.890) but not for RV (r=0.882/0.930, ICC=0.663/0.544). Measurement errors were significant only for EDV of LV using the two-dimensional method. Similar reproducibility was found for LV measurements, but the three-dimensional method provided greater reproducibility for RV measurements than the two-dimensional. The threshold value supported three-dimensional method provides reproducible cardiac ventricular volume measurements, comparable to those obtained using the short-axis Simpson based method. (orig.)

  14. Verification of the Robin and Graham classification system of hip disease in cerebral palsy using three-dimensional computed tomography.

    Science.gov (United States)

    Gose, Shinichi; Sakai, Takashi; Shibata, Toru; Akiyama, Keisuke; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2011-12-01

    We evaluated the validity of the Robin and Graham classification system of hip disease in cerebral palsy (CP) using three-dimensional computed tomography in young people with CP. A total of 91 hips in 91 consecutive children with bilateral spastic CP (57 males, 34 females; nine classified at Gross Motor Function Classification System level II, 42 at level III, 32 at level IV, and eight at level V; mean age 5 y 2 mo, SD 11 mo; range 2-6 y) were investigated retrospectively using anteroposterior plain radiographs and three-dimensional computed tomography (3D-CT) of the hip. The migration percentage was calculated on plain radiographs and all participants were classified into four groups according to migration percentage: grade II, migration percentage ≥ 10% but ≤ 15%, (four hips), grade III, migration percentage >15% but ≤ 30%, (20 hips); grade IV, migration percentage >30% but <100%, (63 hips); and grade V, migration percentage ≥ 100%, (four hips). The lateral opening angle and the sagittal inclination angle of the acetabulum, the neck-shaft angle, and the femoral anteversion of the femur were measured on 3D-CT. The three-dimensional quantitative evaluation indicated that there were significant differences in the lateral opening angle and the neck-shaft angle between the four groups (Kruskal-Wallis test, p ≤ 0.001). This three-dimensional evaluation supports the validation of the Robin and Graham classification system for hip disease in 2- to 7-year-olds with CP. © The Authors. Developmental Medicine & Child Neurology © 2011 Mac Keith Press.

  15. Automated computation of femoral angles in dogs from three-dimensional computed tomography reconstructions: Comparison with manual techniques.

    Science.gov (United States)

    Longo, F; Nicetto, T; Banzato, T; Savio, G; Drigo, M; Meneghello, R; Concheri, G; Isola, M

    2018-02-01

    The aim of this ex vivo study was to test a novel three-dimensional (3D) automated computer-aided design (CAD) method (aCAD) for the computation of femoral angles in dogs from 3D reconstructions of computed tomography (CT) images. The repeatability and reproducibility of three manual radiography, manual CT reconstructions and the aCAD method for the measurement of three femoral angles were evaluated: (1) anatomical lateral distal femoral angle (aLDFA); (2) femoral neck angle (FNA); and (3) femoral torsion angle (FTA). Femoral angles of 22 femurs obtained from 16 cadavers were measured by three blinded observers. Measurements were repeated three times by each observer for each diagnostic technique. Femoral angle measurements were analysed using a mixed effects linear model for repeated measures to determine the levels of intra-observer agreement (repeatability) and inter-observer agreement (reproducibility). Repeatability and reproducibility of measurements using the aCAD method were excellent (intra-class coefficients, ICCs≥0.98) for all three angles assessed. Manual radiography and CT exhibited excellent agreement for the aLDFA measurement (ICCs≥0.90). However, FNA repeatability and reproducibility were poor (ICCscomputation of the 3D aCAD method provided the highest repeatability and reproducibility among the tested methodologies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Respiratory impedance is correlated with airway narrowing in asthma using three-dimensional computed tomography.

    Science.gov (United States)

    Karayama, M; Inui, N; Mori, K; Kono, M; Hozumi, H; Suzuki, Y; Furuhashi, K; Hashimoto, D; Enomoto, N; Fujisawa, T; Nakamura, Y; Watanabe, H; Suda, T

    2018-03-01

    Respiratory impedance comprises the resistance and reactance of the respiratory system and can provide detailed information on respiratory function. However, details of the relationship between impedance and morphological airway changes in asthma are unknown. We aimed to evaluate the correlation between imaging-based airway changes and respiratory impedance in patients with asthma. Respiratory impedance and spirometric data were evaluated in 72 patients with asthma and 29 reference subjects. We measured the intraluminal area (Ai) and wall thickness (WT) of third- to sixth-generation bronchi using three-dimensional computed tomographic analyses, and values were adjusted by body surface area (BSA, Ai/BSA, and WT/the square root (√) of BSA). Asthma patients had significantly increased respiratory impedance, decreased Ai/BSA, and increased WT/√BSA, as was the case in those without airflow limitation as assessed by spirometry. Ai/BSA was inversely correlated with respiratory resistance at 5 Hz (R5) and 20 Hz (R20). R20 had a stronger correlation with Ai/BSA than did R5. Ai/BSA was positively correlated with forced expiratory volume in 1 second/forced vital capacity ratio, percentage predicted forced expiratory volume in 1 second, and percentage predicted mid-expiratory flow. WT/√BSA had no significant correlation with spirometry or respiratory impedance. Respiratory resistance is associated with airway narrowing. © 2018 John Wiley & Sons Ltd.

  17. Three-dimensional monochromatic x-ray computed tomography using synchrotron radiation

    Science.gov (United States)

    Saito, Tsuneo; Kudo, Hiroyuki; Takeda, Tohoru; Itai, Yuji; Tokumori, Kenji; Toyofuku, Fukai; Hyodo, Kazuyuki; Ando, Masami; Nishimura, Katsuyuki; Uyama, Chikao

    1998-08-01

    We describe a technique of 3D computed tomography (3D CT) using monochromatic x rays generated by synchrotron radiation, which performs a direct reconstruction of a 3D volume image of an object from its cone-beam projections. For the development, we propose a practical scanning orbit of the x-ray source to obtain complete 3D information on an object, and its corresponding 3D image reconstruction algorithm. The validity and usefulness of the proposed scanning orbit and reconstruction algorithm were confirmed by computer simulation studies. Based on these investigations, we have developed a prototype 3D monochromatic x-ray CT using synchrotron radiation, which provides exact 3D reconstruction and material-selective imaging by using the K-edge energy subtraction technique.

  18. Micro-computed tomography assessment of human alveolar bone: bone density and three-dimensional micro-architecture.

    Science.gov (United States)

    Kim, Yoon Jeong; Henkin, Jeffrey

    2015-04-01

    Micro-computed tomography (micro-CT) is a valuable means to evaluate and secure information related to bone density and quality in human necropsy samples and small live animals. The aim of this study was to assess the bone density of the alveolar jaw bones in human cadaver, using micro-CT. The correlation between bone density and three-dimensional micro architecture of trabecular bone was evaluated. Thirty-four human cadaver jaw bone specimens were harvested. Each specimen was scanned with micro-CT at resolution of 10.5 μm. The bone volume fraction (BV/TV) and the bone mineral density (BMD) value within a volume of interest were measured. The three-dimensional micro architecture of trabecular bone was assessed. All the parameters in the maxilla and the mandible were subject to comparison. The variables for the bone density and the three-dimensional micro architecture were analyzed for nonparametric correlation using Spearman's rho at the significance level of p architecture parameters were consistently higher in the mandible, up to 3.3 times greater than those in the maxilla. The most linear correlation was observed between BV/TV and BMD, with Spearman's rho = 0.99 (p = .01). Both BV/TV and BMD were highly correlated with all micro architecture parameters with Spearman's rho above 0.74 (p = .01). Two aspects of bone density using micro-CT, the BV/TV and BMD, are highly correlated with three-dimensional micro architecture parameters, which represent the quality of trabecular bone. This noninvasive method may adequately enhance evaluation of the alveolar bone. © 2013 Wiley Periodicals, Inc.

  19. Validation of phalanx bone three-dimensional surface segmentation from computed tomography images using laser scanning

    Energy Technology Data Exchange (ETDEWEB)

    DeVries, Nicole A.; Gassman, Esther E.; Kallemeyn, Nicole A. [The University of Iowa, Department of Biomedical Engineering, Center for Computer Aided Design, Iowa City, IA (United States); Shivanna, Kiran H. [The University of Iowa, Center for Computer Aided Design, Iowa City, IA (United States); Magnotta, Vincent A. [The University of Iowa, Department of Biomedical Engineering, Department of Radiology, Center for Computer Aided Design, Iowa City, IA (United States); Grosland, Nicole M. [The University of Iowa, Department of Biomedical Engineering, Department of Orthopaedics and Rehabilitation, Center for Computer Aided Design, Iowa City, IA (United States)

    2008-01-15

    To examine the validity of manually defined bony regions of interest from computed tomography (CT) scans. Segmentation measurements were performed on the coronal reformatted CT images of the three phalanx bones of the index finger from five cadaveric specimens. Two smoothing algorithms (image-based and Laplacian surface-based) were evaluated to determine their ability to represent accurately the anatomic surface. The resulting surfaces were compared with laser surface scans of the corresponding cadaveric specimen. The average relative overlap between two tracers was 0.91 for all bones. The overall mean difference between the manual unsmoothed surface and the laser surface scan was 0.20 mm. Both image-based and Laplacian surface-based smoothing were compared; the overall mean difference for image-based smoothing was 0.21 mm and 0.20 mm for Laplacian smoothing. This study showed that manual segmentation of high-contrast, coronal, reformatted, CT datasets can accurately represent the true surface geometry of bones. Additionally, smoothing techniques did not significantly alter the surface representations. This validation technique should be extended to other bones, image segmentation and spatial filtering techniques. (orig.)

  20. Three-dimensional localization of impacted canines and root resorption assessment using cone beam computed tomography.

    Science.gov (United States)

    Almuhtaseb, Eyad; Mao, Jing; Mahony, Derek; Bader, Rawan; Zhang, Zhi-xing

    2014-06-01

    The purpose of this study was to develop a new way to localize the impacted canines from three dimensions and to investigate the root resorption of the adjacent teeth by using cone beam computed tomography (CBCT). Forty-six patients undergoing orthodontic treatments and having impacted canines in Tongji Hospital were examined. The images of CBCT scans were obtained from KaVo 3D exam vision. Angular and linear measurements of the cusp tip and root apex according to the three planes (mid-sagittal, occlusal and frontal) have been taken using the cephalometric tool of the InVivo Dental Anatomage Version 5.1.10. The measurements of the angular and linear coordinates of the maxillary and mandibular canines were obtained. Using this technique the operators could envision the location of the impacted canine according to the three clinical planes. Adjacent teeth root resorption of 28.26 % was in the upper lateral incisors while 17.39% in upper central incisors, but no lower root resorption was found in our samples. Accurate and reliable localization of the impacted canines could be obtained from the novel analysis system, which offers a better surgical and orthodontic treatment for the patients with impacted canines.

  1. Validation of phalanx bone three-dimensional surface segmentation from computed tomography images using laser scanning

    International Nuclear Information System (INIS)

    DeVries, Nicole A.; Gassman, Esther E.; Kallemeyn, Nicole A.; Shivanna, Kiran H.; Magnotta, Vincent A.; Grosland, Nicole M.

    2008-01-01

    To examine the validity of manually defined bony regions of interest from computed tomography (CT) scans. Segmentation measurements were performed on the coronal reformatted CT images of the three phalanx bones of the index finger from five cadaveric specimens. Two smoothing algorithms (image-based and Laplacian surface-based) were evaluated to determine their ability to represent accurately the anatomic surface. The resulting surfaces were compared with laser surface scans of the corresponding cadaveric specimen. The average relative overlap between two tracers was 0.91 for all bones. The overall mean difference between the manual unsmoothed surface and the laser surface scan was 0.20 mm. Both image-based and Laplacian surface-based smoothing were compared; the overall mean difference for image-based smoothing was 0.21 mm and 0.20 mm for Laplacian smoothing. This study showed that manual segmentation of high-contrast, coronal, reformatted, CT datasets can accurately represent the true surface geometry of bones. Additionally, smoothing techniques did not significantly alter the surface representations. This validation technique should be extended to other bones, image segmentation and spatial filtering techniques. (orig.)

  2. Colon dissection: a new three-dimensional reconstruction tool for computed tomography colonography

    International Nuclear Information System (INIS)

    Roettgen, R.; Fischbach, F.; Plotkin, M.; Herzog, H.; Freund, T.; Schroeder, R. J.; Felix, R.

    2005-01-01

    Purpose: To improve the sensitivity of computed tomography (CT) colonography in the detection of polyps by comparing the 3D reconstruction tool 'colon dissection' and endoluminal view (virtual colonoscopy) with axial 2D reconstructions. Material and Methods: Forty-eight patients (22 M, 26 F, mean age 57±21) were studied after intra-anal air insufflation in the supine and prone positions using a 16-slice helical CT (16x0.625 mm, pitch 1.7; detector rotation time 0.5 s; 160 mAs und 120 kV) and conventional colonoscopy. Two radiologists blinded to the results of the conventional colonoscopy analyzed the 3D reconstruction in virtual-endoscopy mode, in colon-dissection mode, and axial 2D slices. Results: Conventional colonoscopy revealed a total of 35 polyps in 15 patients; 33 polyps were disclosed by CT methods. Sensitivity and specificity for detecting colon polyps were 94% and 94%, respectively, when using the 'colon dissection', 89% and 94% when using 'virtual endoscopy', and 62% and 100% when using axial 2D reconstruction. Sensitivity in relation to the diameter of colon polyps with 'colon dissection', 'virtual colonoscopy', and axial 2D-slices was: polyps with a diameter >5.0 mm, 100%, 100%, and 71%, respectively; polyps with a diameter of between 3 and 4.9 mm, 92%, 85%, and 46%; and polyps with a diameter <3 mm, 89%, 78%, and 56%. The difference between 'virtual endoscopy' and 'colon dissection' in diagnosing polyps up to 4.9 mm in diameter was statistically significant. Conclusion: 3D reconstruction software 'colon dissection' improves sensitivity of CT colonography compared with the endoluminal view

  3. Three-dimensional computed tomography measurement accuracy of varying Hill-Sachs lesion size.

    Science.gov (United States)

    Ho, Anthony; Kurdziel, Michael D; Koueiter, Denise M; Wiater, J Michael

    2018-02-01

    The glenoid track concept has been proposed to correlate shoulder stability with bone loss. Accurate assessment of Hill-Sachs lesion size preoperatively may affect surgical planning and postoperative outcomes; however, no measurement method has been universally accepted. This study aimed to assess the accuracy and reliability of measuring Hill-Sachs lesion sizes using 3-dimensional (3D) computed tomography (CT). Nine polyurethane humerus bone substitutes were used to create Hill-Sachs lesions of varying sizes with a combination of lesion depth (shallow, intermediate, and deep) and width (small, medium, and large). Specimens were scanned with a clinical CT scanner for size measurements and a micro-CT scanner for measurement of true lesion size. Six evaluators repeated measurements twice in a 2-week interval. Scans were measured by use of 3D CT reconstructions for length, width, and Hill-Sachs interval and with use of 2D CT for depth. The interclass correlation coefficient evaluated interobserver and intraobserver variability and percentage error, and Student t-tests assessed measurement accuracy. Interclass correlation coefficient reliability demonstrated strong agreement for all variables measured (0.856-0.975). Percentage error between measured length and measured depth and the true measurement significantly varied with respect to both lesion depth (P = .003 and P = .005, respectively) and lesion size (P = .049 and P = .004, respectively). The 3D CT imaging is effective and reproducible in determining lesion size. Determination of Hill-Sachs interval width is also reliable when it is applied to the glenoid track concept. Measured values on 3D and 2-dimensional imaging using a conventional CT scanner may slightly underestimate true measurements. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  4. Accuracy of three-dimensional cone beam computed tomography digital model measurements compared with plaster study casts

    Directory of Open Access Journals (Sweden)

    Shuaib Al Ali

    2017-01-01

    Full Text Available Purpose: The purpose of this study was to assess the accuracy of three-dimensional (3D cone beam computed tomography (CBCT study casts by comparing with direct measurements taken from plaster study casts. Materials and Methods: The dental arches of 30 patient subjects were imaged with a Kodak 9300 3D CBCT devise; Anatomodels were created and in vivo 5 imaging software was used to measure 10 dental arch variables which were compared to measurements of plaster study casts. Results: Three of the 10 variables, i.e., overbite, maxillary intermolar width, and arch length, were found significantly smaller (P < 0.05 using the Anatomodels following nonparametric Wilcoxon signed-rank testing. None of the differences found in the study averaged <0.5 mm. Conclusions: 3D CBCT imaging provided clinically acceptable accuracy for dental arch analysis. 3D CBCT imaging tended to underestimate the actual measurement compared to plaster study casts.

  5. Newly defined landmarks for a three-dimensionally based cephalometric analysis: a retrospective cone-beam computed tomography scan review.

    Science.gov (United States)

    Lee, Moonyoung; Kanavakis, Georgios; Miner, R Matthew

    2015-01-01

    To identify two novel three-dimensional (3D) cephalometric landmarks and create a novel three-dimensionally based anteroposterior skeletal measurement that can be compared with traditional two-dimensional (2D) cephalometric measurements in patients with Class I and Class II skeletal patterns. Full head cone-beam computed tomography (CBCT) scans of 100 patients with all first molars in occlusion were obtained from a private practice. InvivoDental 3D (version 5.1.6, Anatomage, San Jose, Calif) was used to analyze the CBCT scans in the sagittal and axial planes to create new landmarks and a linear 3D analysis (M measurement) based on maxillary and mandibular centroids. Independent samples t-test was used to compare the mean M measurement to traditional 2D cephalometric measurements, ANB and APDI. Interexaminer and intraexaminer reliability were evaluated using 2D and 3D scatterplots. The M measurement, ANB, and APDI could statistically differentiate between patients with Class I and Class II skeletal patterns (P < .001). The M measurement exhibited a correlation coefficient (r) of -0.79 and 0.88 with APDI and ANB, respectively. The overall centroid landmarks and the M measurement combine 2D and 3D methods of imaging; the measurement itself can distinguish between patients with Class I and Class II skeletal patterns and can serve as a potential substitute for ANB and APDI. The new three-dimensionally based landmarks and measurements are reliable, and there is great potential for future use of 3D analyses for diagnosis and research.

  6. Three-dimensional prediction of the human eyeball and canthi for craniofacial reconstruction using cone-beam computed tomography.

    Science.gov (United States)

    Kim, Sang-Rok; Lee, Kyung-Min; Cho, Jin-Hyoung; Hwang, Hyeon-Shik

    2016-04-01

    An anatomical relationship between the hard and soft tissues of the face is mandatory for facial reconstruction. The purpose of this study was to investigate the positions of the eyeball and canthi three-dimensionally from the relationships between the facial hard and soft tissues using cone-beam computed tomography (CBCT). CBCT scan data of 100 living subjects were used to obtain the measurements of facial hard and soft tissues. Stepwise multiple regression analyses were carried out using the hard tissue measurements in the orbit, nasal bone, nasal cavity and maxillary canine to predict the most probable positions of the eyeball and canthi within the orbit. Orbital width, orbital height, and orbital depth were strong predictors of the eyeball and canthi position. Intercanine width was also a predictor of the mediolateral position of the eyeball. Statistically significant regression models for the positions of the eyeball and canthi could be derived from the measurements of orbit and maxillary canine. These results suggest that CBCT data can be useful in predicting the positions of the eyeball and canthi three-dimensionally. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Three-dimensional computed tomography of the reconstructed lower urinary tract: technique and findings

    International Nuclear Information System (INIS)

    Frank, R.; Frede, T.; Eder, R.; Recheis, W.; Knapp, R.; zur Nedden, D.; Stenzl, A.; Bartsch, G.

    1998-01-01

    The aim of this pilot study in 54 patients was to improve the visualization of the anatomy and postoperative changes in the pelvic topography after bilateral ureteroileal urethrostomy, using surface rendering of electron beam CT (EBCT) data for the 3D display. Fifty-four patients (39 men and 15 women) were scanned with an EBCT unit between 3 and 110 months after performing orthotopic ureteroileal urethrostomy (''Hemi-Kock'') or ureteroileal rectosigmoidostomy. Various parameters and spatial viewing points were used in the 3D reconstruction, which was performed interactively on external workstations with commercially available software. The anti-reflux nipple was visualized as a distinct structure in all patients. In 8 patients with an interval of more than 12 months between surgery and CT, the pouch had developed an ovoid shape almost indistinguishable from the original bladder. The segmented data sets were partly animated to display the anatomy as virtual endoscopy. Three-dimensional depiction and virtual endoscopy of the neobladder using EBCT are a new way of imaging the postoperative anatomy. Its clinical efficacy in the diagnosis of inconclusive postoperative morbidity, especially voiding problems, and planning of necessary therapy have to be the subject of further evaluation. (orig.)

  8. Three-dimensional segmentation of pulmonary artery volume from thoracic computed tomography imaging

    Science.gov (United States)

    Lindenmaier, Tamas J.; Sheikh, Khadija; Bluemke, Emma; Gyacskov, Igor; Mura, Marco; Licskai, Christopher; Mielniczuk, Lisa; Fenster, Aaron; Cunningham, Ian A.; Parraga, Grace

    2015-03-01

    Chronic obstructive pulmonary disease (COPD), is a major contributor to hospitalization and healthcare costs in North America. While the hallmark of COPD is airflow limitation, it is also associated with abnormalities of the cardiovascular system. Enlargement of the pulmonary artery (PA) is a morphological marker of pulmonary hypertension, and was previously shown to predict acute exacerbations using a one-dimensional diameter measurement of the main PA. We hypothesized that a three-dimensional (3D) quantification of PA size would be more sensitive than 1D methods and encompass morphological changes along the entire central pulmonary artery. Hence, we developed a 3D measurement of the main (MPA), left (LPA) and right (RPA) pulmonary arteries as well as total PA volume (TPAV) from thoracic CT images. This approach incorporates segmentation of pulmonary vessels in cross-section for the MPA, LPA and RPA to provide an estimate of their volumes. Three observers performed five repeated measurements for 15 ex-smokers with ≥10 pack-years, and randomly identified from a larger dataset of 199 patients. There was a strong agreement (r2=0.76) for PA volume and PA diameter measurements, which was used as a gold standard. Observer measurements were strongly correlated and coefficients of variation for observer 1 (MPA:2%, LPA:3%, RPA:2%, TPA:2%) were not significantly different from observer 2 and 3 results. In conclusion, we generated manual 3D pulmonary artery volume measurements from thoracic CT images that can be performed with high reproducibility. Future work will involve automation for implementation in clinical workflows.

  9. Cadaveric and three-dimensional computed tomography study of the morphology of the scapula with reference to reversed shoulder prosthesis.

    Science.gov (United States)

    Torrens, Carlos; Corrales, Monica; Gonzalez, Gemma; Solano, Alberto; Cáceres, Enrique

    2008-10-10

    The purpose of this study is to analyze the morphology of the scapula with reference to the glenoid component implantation in reversed shoulder prosthesis, in order to improve primary fixation of the component. Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed to determine the anterior and posterior length of the glenoid neck, the angle between the glenoid surface and the upper posterior column of the scapula and the angle between the major craneo-caudal glenoid axis and the base of the coracoid process and the upper posterior column. The anterior and posterior length of glenoid neck was classified into two groups named "short-neck" and "long-neck" with significant differences between them. The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (mean 50 degrees-52 degrees ) and type II (mean 62.50 degrees-64 degrees ), with significant differences between them (p craneo-caudal glenoid axis and the base of the coracoid process averaged 18,25 degrees while the angle with the upper posterior column of the scapula averaged 8 degrees . Scapular morphological variability advices for individual adjustments of glenoid component implantation in reversed total shoulder prosthesis. Three-dimensional computed tomography of the scapula constitutes an important tool when planning reversed prostheses implantation.

  10. Cadaveric and three-dimensional computed tomography study of the morphology of the scapula with reference to reversed shoulder prosthesis

    Directory of Open Access Journals (Sweden)

    Solano Alberto

    2008-10-01

    Full Text Available Abstract Purpose The purpose of this study is to analyze the morphology of the scapula with reference to the glenoid component implantation in reversed shoulder prosthesis, in order to improve primary fixation of the component. Methods Seventy-three 3-dimensional computed tomography of the scapula and 108 scapular dry specimens were analyzed to determine the anterior and posterior length of the glenoid neck, the angle between the glenoid surface and the upper posterior column of the scapula and the angle between the major craneo-caudal glenoid axis and the base of the coracoid process and the upper posterior column. Results The anterior and posterior length of glenoid neck was classified into two groups named "short-neck" and "long-neck" with significant differences between them. The angle between the glenoid surface and the upper posterior column of the scapula was also classified into two different types: type I (mean 50°–52° and type II (mean 62,50°–64°, with significant differences between them (p Conclusion Scapular morphological variability advices for individual adjustments of glenoid component implantation in reversed total shoulder prosthesis. Three-dimensional computed tomography of the scapula constitutes an important tool when planning reversed prostheses implantation.

  11. [Three-dimensional computed tomography analysis and clinical application of sacroiliac screw placement].

    Science.gov (United States)

    Yin, Y C; Zhang, R P; Li, S L; Hou, Z Y; Chen, W; Zhang, Y Z

    2018-03-01

    Objective: To evaluate the possibility of transverse sacroiliac screw placement in different segments of the sacrum. Methods: Data of 80 pelvic CT scans (slice thickness ≤1.0 mm) archived in CT department of the Third Hospital of Hebei Medical University from September 2016 to October 2017 were retrospectively collected. Mimics software was used to rebuild the pelvis three-dimensional model. According to whether the sacral 1(S(1)) segment could place the transverse sacroiliac screws or not, all the sacrums were divided into normal group ( n =55) and dysmorphic group ( n =25). Simulation the S(1), sacral 2(S(2)) transverse sacroiliac screw placement in 3-Matic software. Analysis whether there was any difference in maximum diameter and length of S(2) transverse sacroiliac screw between the normal group and the dysmorphic group. The pelvic CT data of the dysmorphic group were measured, and the optimal tilt angle and length of the oblique S(1) screw were obtained. The feasibility of transverse sacroiliac screw insertion in sacral 3(S(3)) segment was evaluated. t -test, rank sum test, and χ(2) test was used to analyze data, respectively. Results: In the dysmorphic group, the largest diameter of the S(1) transverse screw was (4.9±1.6)mm, and the normal group was (13.6±3.6)mm ( t =-15.07, P =0.00). In the dysmorphic group, the largest diameter of S(2) transverse screw was (13.8±3.0)mm, and was (12.4±2.2)mm in the normal group( t =2.11, P =0.04). There was no significant difference in the length of S(2) transverse sacroiliac screw between the two groups ( t =0.47, P =0.64). In the dysmorphic group, the anterior vertebral height of S(1) was (23.1±4.0)mm, which was significantly higher than that of the normal group ((14.1±4.2)mm)( t =9.01, P =0.00). The angle of S(1)S(2) in the dysmorphic group was 10.9°(3.8°, 17.6°), which was significantly larger than that of the normal group (2.0°(1.0°, 2.0°) ( Z =-4.03, P =0.00). In the dysmorphic group, the incline angle

  12. Fast parallel algorithm for three-dimensional distance-driven model in iterative computed tomography reconstruction

    International Nuclear Information System (INIS)

    Chen Jian-Lin; Li Lei; Wang Lin-Yuan; Cai Ai-Long; Xi Xiao-Qi; Zhang Han-Ming; Li Jian-Xin; Yan Bin

    2015-01-01

    The projection matrix model is used to describe the physical relationship between reconstructed object and projection. Such a model has a strong influence on projection and backprojection, two vital operations in iterative computed tomographic reconstruction. The distance-driven model (DDM) is a state-of-the-art technology that simulates forward and back projections. This model has a low computational complexity and a relatively high spatial resolution; however, it includes only a few methods in a parallel operation with a matched model scheme. This study introduces a fast and parallelizable algorithm to improve the traditional DDM for computing the parallel projection and backprojection operations. Our proposed model has been implemented on a GPU (graphic processing unit) platform and has achieved satisfactory computational efficiency with no approximation. The runtime for the projection and backprojection operations with our model is approximately 4.5 s and 10.5 s per loop, respectively, with an image size of 256×256×256 and 360 projections with a size of 512×512. We compare several general algorithms that have been proposed for maximizing GPU efficiency by using the unmatched projection/backprojection models in a parallel computation. The imaging resolution is not sacrificed and remains accurate during computed tomographic reconstruction. (paper)

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

    International Nuclear Information System (INIS)

    Zhang Aidong; Sun Lingxia; Zhou Ying; Ye Yunchang

    2009-01-01

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

  14. Comparison of Conventional Versus Spiral Computed Tomography with Three Dimensional Reconstruction in Chronic Otitis Media with Ossicular Chain Destruction

    International Nuclear Information System (INIS)

    Naghibi, Saeed; Seifirad, Sirous; Adami Dehkordi, Mahboobeh; Einolghozati, Sasan; Ghaffarian Eidgahi Moghadam, Nafiseh; Akhavan Rezayat, Amir; Seifirad, Soroush

    2016-01-01

    Chronic otitis media (COM) can be treated with tympanoplasty with or without mastoidectomy. In patients who have undergone middle ear surgery, three-dimensional spiral computed tomography (CT) scan plays an important role in optimizing surgical planning. This study was performed to compare the findings of three-dimensional reconstructed spiral and conventional CT scan of ossicular chain study in patients with COM. Fifty patients enrolled in the study underwent plane and three dimensional CT scan (PHILIPS-MX 8000). Ossicles changes, mastoid cavity, tympanic cavity, and presence of cholesteatoma were evaluated. Results of the two methods were then compared and interpreted by a radiologist, recorded in questionnaires, and analyzed. Logistic regression test and Kappa coefficient of agreement were used for statistical analyses. Sixty two ears with COM were found in physical examination. A significant difference was observed between the findings of the two methods in ossicle erosion (11.3% in conventional CT vs. 37.1% in spiral CT, P = 0.0001), decrease of mastoid air cells (82.3% in conventional CT vs. 93.5% in spiral CT, P = 0.001), and tympanic cavity opacity (12.9% in conventional CT vs. 40.3% in spiral CT, P=0.0001). No significant difference was observed between the findings of the two methods in ossicle destruction (6.5% conventional CT vs. 56.4% in spiral CT, P = 0.125), and presence of cholesteatoma (3.2% in conventional CT vs. 42% in spiral CT, P = 0.172). In this study, spiral CT scan demonstrated ossicle dislocation in 9.6%, decrease of mastoid air cells in 4.8%, and decrease of volume in the tympanic cavity in 1.6%; whereas, none of these findings were reported in the patients' conventional CT scans. Spiral-CT scan is superior to conventional CT in the diagnosis of lesions in COM before operation. It can be used for detailed evaluation of ossicular chain in such patients

  15. Construction of three-dimensional tooth model by micro-computed tomography and application for data sharing.

    Science.gov (United States)

    Kato, A; Ohno, N

    2009-03-01

    The study of dental morphology is essential in terms of phylogeny. Advances in three-dimensional (3D) measurement devices have enabled us to make 3D images of teeth without destruction of samples. However, raw fundamental data on tooth shape requires complex equipment and techniques. An online database of 3D teeth models is therefore indispensable. We aimed to explore the basic methodology for constructing 3D teeth models, with application for data sharing. Geometric information on the human permanent upper left incisor was obtained using micro-computed tomography (micro-CT). Enamel, dentine, and pulp were segmented by thresholding of different gray-scale intensities. Segmented data were separately exported in STereo-Lithography Interface Format (STL). STL data were converted to Wavefront OBJ (OBJect), as many 3D computer graphics programs support the Wavefront OBJ format. Data were also applied to Quick Time Virtual Reality (QTVR) format, which allows the image to be viewed from any direction. In addition to Wavefront OBJ and QTVR data, the original CT series were provided as 16-bit Tag Image File Format (TIFF) images on the website. In conclusion, 3D teeth models were constructed in general-purpose data formats, using micro-CT and commercially available programs. Teeth models that can be used widely would benefit all those who study dental morphology.

  16. Three-dimensional observations of the incisive canal and the surrounding bone using cone-beam computed tomography

    International Nuclear Information System (INIS)

    Asaumi, Rieko; Kawai, Taisuke; Sato, Iwao; Yoshida, Shunji; Yosue, Takashi

    2010-01-01

    The shape of the anterior region of the maxilla is critical when planning implant treatment. The purpose of the present study was to assess the typical morphology of the incisive canal and surrounding bone. In total, 70 maxillae of Japanese dry skulls were used after being divided into dentate and edentulous groups. Cone-beam computed tomography (CBCT) images of the maxilla were acquired by using standardized methods. Using the anterior nasal spine as a reference point, the change in position was measured and analyzed statistically. Also, three-dimensional (3-D) images of the incisive canal were classified into five subsets: cylinder, groove, penetration, bifurcation at the superior portion, and bifurcation at the inferior portion. The quantity of alveolar bone in the incisor region was greatly reduced from the alveolar ridge and labial surface. Moreover, the vertical position of the incisive foramen was significantly (P<0.05) superior in the edentulous groups. Regarding the classification of maxillae by the 3-D shape of the incisive canal, many canals were cylindrical. Horizontal bone reduction from the labial side and vertical bone reduction from the alveolar crest were conspicuous; thus, the angle of the anterior alveolar bone changed after the loss of teeth. The incisive canal diameter in the edentulous group was larger than in the dentate group. The nondestructive assessment of the incisive canals and surrounding bone with CBCT showed two typical shapes for the presence or absence of the incisors. These findings indicate the importance of image diagnosis before esthetic restoration. (author)

  17. Reduction of metal artifact in three-dimensional computed tomography (3D CT) with dental impression materials.

    Science.gov (United States)

    Park, W S; Kim, K D; Shin, H K; Lee, S H

    2007-01-01

    Metal Artifact still remains one of the main drawbacks in craniofacial Three-Dimensional Computed Tomography (3D CT). In this study, we tried to test the efficacy of additional silicone dental impression materials as a "tooth shield" for the reduction of metal artifact caused by metal restorations and orthodontic appliances. 6 phantoms with 4 teeth were prepared for this in vitro study. Orthodontic bracket, bands and amalgam restorations were placed in each tooth to reproduce various intraoral conditions. Standardized silicone shields were fabricated and placed around the teeth. CT image acquisition was performed with and without silicone shields. Maximum value, mean, and standard deviation of Hounsfield Units (HU) were compared with the presence of silicone shields. In every situation, metal artifacts were reduced in quality and quantity when silicone shields are used. Amalgam restoration made most serious metal artifact. Silicone shields made by dental impression material might be effective way to reduce the metal artifact caused by dental restoration and orthodontic appliances. This will help more excellent 3D image from 3D CT in craniofacial area.

  18. Three-dimensional evaluation of pharyngeal airway in individuals with varying growth patterns using cone beam computed tomography

    Directory of Open Access Journals (Sweden)

    Rohan Diwakar

    2015-01-01

    Full Text Available Introduction: The purpose of this study was to evaluate the pharyngeal airway volume in individuals with different vertical growth patterns. Methods: Cone beam computed tomography scans were evaluated of 40 subjects with the age range from 14 to 25 years and were divided into three groups. Horizontal growers consisted of 13 subjects, normal growers consisted of 14 subjects, and the vertical growers consisted of 13 subjects. The pharyngeal airway volume was measured using In Vivo Dental 5.1 software (Anatomage, Anatomy Imaging Software, San Jose, CA, USA. Results: The results obtained were analyzed statistically. The statistical test used for the analysis of the result was Student′s t-test. The independent t-test was done to compare the mean of the pharyngeal airway between the normal growers and horizontal growers and between the normal growers and the vertical growers. No statistically significant difference between the three groups was found in the volumetric measurements of the various sections of airway. Conclusions: Pharyngeal airway volume does not differ significantly in different vertical jaw relationships. It was possible to evaluate the pharyngeal airway volume three dimensionally.

  19. Quantitative three-dimensional analysis of root canal curvature in maxillary first molars using micro-computed tomography.

    Science.gov (United States)

    Lee, Jong-Ki; Ha, Byung-Hyun; Choi, Jeong-Ho; Heo, Seok-Mo; Perinpanayagam, Hiran

    2006-10-01

    In endodontic therapy, access and instrumentation are strongly affected by root canal curvature. However, the few studies that have actually measured curvature are mostly from two-dimensional radiographs. The purpose of this study was to measure the three-dimensional (3D) canal curvature in maxillary first molars using micro-computed tomography (microCT) and mathematical modeling. Extracted maxillary first molars (46) were scanned by microCT (502 image slices/tooth, 1024 X 1024 pixels, voxel size of 19.5 x 19.5 x 39.0 microm) and their canals reconstructed by 3D modeling software. The intersection of major and minor axes in the canal space of each image slice were connected to create an imaginary central axis for each canal. The radius of curvature of the tangential circle was measured and inverted as a measure of curvature using custom-made mathematical modeling software. Root canal curvature was greatest in the apical third and least in the middle third for all canals. The greatest curvatures were in the mesiobuccal (MB) canal (0.76 +/- 0.48 mm(-1)) with abrupt curves, and the least curvatures were in the palatal (P) canal (0.38 +/- 0.34 mm(-1)) with a gradual curve. This study has measured the 3D curvature of root canals in maxillary first molars and reinforced the value of microCT with mathematical modeling.

  20. A cone-beam computed tomography triple scan procedure to obtain a three-dimensional augmented virtual skull model appropriate for orthognathic surgery planning.

    NARCIS (Netherlands)

    Swennen, G.R.J.; Mollemans, W.; Clercq, C. De; Abeloos, J.V.S.; Lamoral, P.; Lippens, F.R.C.; Neyt, N.; Casselman, J.W.; Schutyser, F.A.C.

    2009-01-01

    The aim of this study was to present a new approach to acquire a three-dimensional virtual skull model appropriate for orthognathic surgery planning without the use of plaster dental models and without deformation of the facial soft-tissue mask. A "triple" cone-beam computed tomography (CBCT) scan

  1. The use of a wax bite wafer and a double computed tomography scan procedure to obtain a three-dimensional augmented virtual skull model.

    NARCIS (Netherlands)

    Swennen, G.R.J.; Mommaerts, M.Y.; Abeloos, J.V.S.; Clercq, C. De; Lamoral, P.; Neyt, N.; Casselman, J.W.; Schutyser, F.A.C.

    2007-01-01

    A detailed visualization of the interocclusal relationship is essential in a three-dimensional virtual planning setup for orthognathic and facial orthomorphic surgery. The purpose of this study was to introduce and evaluate the use of a wax bite wafer in combination with a double computed tomography

  2. 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

  3. 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

  4. A comparative study of the deviation of the menton on posteroanterior cephalograms and three dimensional computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Jin; Lee, Sun Gene; Lee, Eun Joo; Kang, Byung Cheol; Lee, Jae Seo; Lim, Hoi Jeong; Yoon, Suk Ja [School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju (Korea, Republic of); Song, In Ja [Dept. of Nursing, Kwangju Women' s University, Gwangju (Korea, Republic of)

    2016-03-15

    Facial asymmetry has been measured by the severity of deviation of the menton (Me) on posteroanterior (PA) cephalograms and three-dimensional (3D) computed tomography (CT). This study aimed to compare PA cephalograms and 3D CT regarding the severity of Me deviation and the direction of the Me. PA cephalograms and 3D CT images of 35 patients who underwent orthognathic surgery (19 males and 16 females, with an average age of 22.1±3.3 years) were retrospectively reviewed in this study. By measuring the distance and direction of the Me from the midfacial reference line and the midsagittal plane in the cephalograms and 3D CT, respectively, the x-coordinates (x1 and x2) of the Me were obtained in each image. The difference between the x-coordinates was calculated and statistical analysis was performed to compare the severity of Me deviation and the direction of the Me in the two imaging modalities. A statistically significant difference in the severity of Me deviation was found between the two imaging modalities (Δx=2.45±2.03 mm, p<0.05) using the one-sample t-test. Statistically significant agreement was observed in the presence of deviation (k=0.64, p<0.05) and in the severity of Me deviation (k=0.27, p<0.05). A difference in the direction of the Me was detected in three patients (8.6%). The severity of the Me deviation was found to vary according to the imaging modality in 16 patients (45.7%). The measurement of Me deviation may be different between PA cephalograms and 3D CT in some patients.

  5. A comparative study of the deviation of the menton on posteroanterior cephalograms and three dimensional computed tomography

    International Nuclear Information System (INIS)

    Lee, Hee Jin; Lee, Sun Gene; Lee, Eun Joo; Kang, Byung Cheol; Lee, Jae Seo; Lim, Hoi Jeong; Yoon, Suk Ja; Song, In Ja

    2016-01-01

    Facial asymmetry has been measured by the severity of deviation of the menton (Me) on posteroanterior (PA) cephalograms and three-dimensional (3D) computed tomography (CT). This study aimed to compare PA cephalograms and 3D CT regarding the severity of Me deviation and the direction of the Me. PA cephalograms and 3D CT images of 35 patients who underwent orthognathic surgery (19 males and 16 females, with an average age of 22.1±3.3 years) were retrospectively reviewed in this study. By measuring the distance and direction of the Me from the midfacial reference line and the midsagittal plane in the cephalograms and 3D CT, respectively, the x-coordinates (x1 and x2) of the Me were obtained in each image. The difference between the x-coordinates was calculated and statistical analysis was performed to compare the severity of Me deviation and the direction of the Me in the two imaging modalities. A statistically significant difference in the severity of Me deviation was found between the two imaging modalities (Δx=2.45±2.03 mm, p<0.05) using the one-sample t-test. Statistically significant agreement was observed in the presence of deviation (k=0.64, p<0.05) and in the severity of Me deviation (k=0.27, p<0.05). A difference in the direction of the Me was detected in three patients (8.6%). The severity of the Me deviation was found to vary according to the imaging modality in 16 patients (45.7%). The measurement of Me deviation may be different between PA cephalograms and 3D CT in some patients

  6. Three-dimensional printing of X-ray computed tomography datasets with multiple materials using open-source data processing.

    Science.gov (United States)

    Sander, Ian M; McGoldrick, Matthew T; Helms, My N; Betts, Aislinn; van Avermaete, Anthony; Owers, Elizabeth; Doney, Evan; Liepert, Taimi; Niebur, Glen; Liepert, Douglas; Leevy, W Matthew

    2017-07-01

    Advances in three-dimensional (3D) printing allow for digital files to be turned into a "printed" physical product. For example, complex anatomical models derived from clinical or pre-clinical X-ray computed tomography (CT) data of patients or research specimens can be constructed using various printable materials. Although 3D printing has the potential to advance learning, many academic programs have been slow to adopt its use in the classroom despite increased availability of the equipment and digital databases already established for educational use. Herein, a protocol is reported for the production of enlarged bone core and accurate representation of human sinus passages in a 3D printed format using entirely consumer-grade printers and a combination of free-software platforms. The comparative resolutions of three surface rendering programs were also determined using the sinuses, a human body, and a human wrist data files to compare the abilities of different software available for surface map generation of biomedical data. Data shows that 3D Slicer provided highest compatibility and surface resolution for anatomical 3D printing. Generated surface maps were then 3D printed via fused deposition modeling (FDM printing). In conclusion, a methodological approach that explains the production of anatomical models using entirely consumer-grade, fused deposition modeling machines, and a combination of free software platforms is presented in this report. The methods outlined will facilitate the incorporation of 3D printed anatomical models in the classroom. Anat Sci Educ 10: 383-391. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  7. Quantification of subarachnoid hemorrhage by three-dimensional computed tomography. Correlation between hematoma volume and symptomatic vasospasm

    International Nuclear Information System (INIS)

    Sato, Taku; Sakuma, Jun; Sasaki, Tatsuya

    2011-01-01

    Subarachnoid hemorrhage (SAH) volume was measured by three-dimensional computed tomography (3D-CT) and the correlation examined between the SAH volume and the occurrence of symptomatic vasospasm (SVS). Experimental (in vitro) hematomas were made with blood obtained from 10 volunteers. The hematoma volume was determined by actual measurements and by 3D-CT using a CT number in the range of 40-80 Hounsfield units (HU) on days 1, 4, 7, 11, and 14. The coefficients on days 1 and 4 were relatively high and the correlation between measured and estimated volumes was significant on days 7, 11, and 14. 3D-CT was also performed in 50 patients with SAH at onset (day 0) and on days 1, 4, 7, and 14. The hematoma volume including the volume of normal structures was automatically calculated (V1). The volume of normal structures (V2) with CT numbers of 40-80 HU was calculated in another 50 patients without intracranial lesions as 12 ml. The total hematoma volume was defined as V1 minus mean V2. The mean SAH volume was 44, 36, 21, 11, and 8 ml on days 0, 1, 4, 7, and 14, respectively. The hematoma volumes were significantly larger in patients with SVS than in patients without SVS at all time points. The minimum hematoma volume in patients with SVS was 92, 76, 42, 24, and 12 ml on days 0, 1, 4, 7, and 14, respectively. This method allows the quantitative determination of SAH volume based on 3D-CT, and may be useful in clinical studies of cerebral vasospasm. (author)

  8. In vivo analysis of acromioclavicular joint motion after hook plate fixation using three-dimensional computed tomography.

    Science.gov (United States)

    Kim, Yoon Sang; Yoo, Yon-Sik; Jang, Seong Wook; Nair, Ayyappan Vijayachandran; Jin, Hyonki; Song, Hyun-Seok

    2015-07-01

    The clavicle hook plate can be used to treat acromioclavicular and coracoclavicular ligament injury or distal clavicular fracture with comminution. However, the hook plate can induce subacromial impingement, resulting in discomfort from the hardware. Our inclusion criteria were (1) men and women aged older than 20 years and (2) the presence of comminuted distal clavicular fractures (Neer type IIB) fixed with a hook plate (Synthes, Oberdorf, Switzerland). Three-dimensional computed tomography was obtained before removal of the hook plate. Seven patients were enrolled prospectively. The mean age was 42 years (range, 24-60 years). Zero degree images and abduction images were obtained. The sagittal cut surface was obtained 5 mm medial from the distal clavicle. The equator of the cut surface of the clavicle was compared with the full abduction model to analyze rotation. The center of the cut surface of the clavicle was compared with the full abduction model to analyze translation. The average difference in rotation of the distal clavicle between both shoulders was 16° (range, 3°-22°; P = .001). The mean difference in anterior translation of the distal clavicle was 2.2 mm (range, -0.7 to 5.6 mm; P = .030). Hook plate fixation at the acromioclavicular joint causes decreased internal rotation and increased anterior translation of the distal clavicle with respect to the medial acromion, indicating that the scapula relative to the thorax has decreased posterior tilting and increased external rotation in shoulders fixed using a hook plate. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  9. Imaging of the Coronary Venous System: Validation of Three-Dimensional Rotational Venous Angiography Against Dual-Source Computed Tomography

    International Nuclear Information System (INIS)

    Knackstedt, Christian; Muehlenbruch, Georg; Mischke, Karl; Bruners, Philipp; Schimpf, Thomas; Frechen, Dirk; Schummers, Georg; Mahnken, Andreas H.; Guenther, Rolf W.; Kelm, Malte; Schauerte, Patrick

    2008-01-01

    Information on the anatomy of the cardiac venous system (CVS) is increasingly important for cardiac resynchronization therapy or percutaneous transvenous mitral valve annuloplasty. Three-dimensional (3D) imaging can further improve the understanding of the relationship of cardiac structures. This study was performed to validate the accuracy of rotational coronary sinus angiography (CSA) displaying the 3D anatomy of the CVS compared to ECG-gated, contrast-enhanced, cardiac dual-source computed tomography (DSCT). Five domestic pigs (60 kg) underwent DSCT using a standardized examination protocol. Using a standard C-arm for fluoroscopy, a rotational CSA was obtained and 3D-image reconstructions performed. Side branches were identified using both methods and enumerated. Vessel visibility was estimated for each side branch and great cardiac vein/anterior interventricular vein. Also, vessel diameters were measured at distinct landmarks, i.e., side branching. The amount of contrast medium was determined and the effective radiation exposure of both methods was calculated. There was no significant difference regarding the vessel diameter of the great cardiac vein/anterior interventricular vein or its side branches. Also, estimation of vessel visibility was not different between the two imaging modalities. Estimated radiation exposure and amount of contrast medium were lower for rotational CSA. In conclusion, a 3D reconstruction of rotational CSA images is possible. All parts of the CVS are well depicted, allowing a 3D overview of the CVS anatomy. On-site 3D visualization might improve decision making during cardiac interventions. In contrast to DSCT, rotational CSA does not demonstrate the anatomy of the mitral annulus or the course of the left circumflex artery.

  10. Quantitative evaluation of native lung hyperinflation after single lung transplantation for emphysema using three-dimensional computed tomography volumetry.

    Science.gov (United States)

    Motoyama, H; Chen, F; Ohsumi, A; Hijiya, K; Takahashi, M; Ohata, K; Yamada, T; Sato, M; Aoyama, A; Bando, T; Date, H

    2014-04-01

    Although double lung transplantation is performed more frequently for emphysema, single lung transplantation (SLT) continues to be performed owing to limited donor organ availability. Native lung hyperinflation (NLH) is a unique complication following SLT for emphysema. Three-dimensional computed tomography (3D-CT) volumetry has been introduced into the field of lung transplantation, which we used to assess NLH in emphysema patients undergoing SLT. The primary purpose of this study was to confirm the effectiveness of 3D-CT volumetry in the evaluation of NLH following SLT for emphysema. In 5 emphysema patients undergoing SLT at Kyoto University Hospital, 3D-CT volumetry data, pulmonary function test results, and clinical and radiological findings were retrospectively evaluated. Three patients did not develop a significant mediastinal shift, whereas the other 2 patients developed a mediastinal shift. In the 3 patients without a mediastinal shift, 3D-CT volumetry did not show a significant increase in native lung volume. These patients had a history of sternotomy prior to lung transplantation and firm adhesion on the mediastinal side was detected during lung transplantation. One of 2 patients with a mediastinal shift developed severe dyspnea with significantly decreased pulmonary function, and 3D-CT volumetry showed a significant increase in the native lung volume. However, the other patient did not show any dyspnea and his native lung volume decreased postoperatively (preoperatively to 6 months postoperatively: +981 mL and -348 mL, respectively). Although bilateral lung transplantation has become preferable for emphysema patients owing to postoperative NLH with SLT, patients with a history of sternotomy prior to lung transplantation might be good candidates for SLT. 3D-CT volumetry may be a useful method for detection of NLH. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Three-dimensional fluorescence lifetime tomography

    International Nuclear Information System (INIS)

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

    2005-01-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores

  12. Kidney lower pole pelvicaliceal anatomy: comparative analysis between intravenous urogram and three-dimensional helical computed tomography.

    Science.gov (United States)

    Rachid Filho, Daibes; Favorito, Luciano A; Costa, Waldemar S; Sampaio, Francisco J B

    2009-12-01

    The aim of our study was to evaluate if there is any advantage of three-dimensional helical computed tomography (3D-HCT) over intravenous urogram (IVU) in the morphometric and morphological analysis of lower pole spatial anatomy of the kidney. We analyzed 52 renal collecting systems in 30 patients, ranging in age from 23 to 80 years. The study compared the following features: (1) the angle formed between the lower infundibulum and the renal pelvis (i.e., lower infundibulum-pelvic angle [IPA]), (2) the lower infundibulum diameter (ID), and (3) the spatial distribution and number of lower pole calices (i.e., caliceal distribution [CD]). The study started with the 3D-HCT images obtained for posterior reconstruction and analysis. Afterward, we obtained anteroposterior and oblique IVU images. For IPA (in degrees) we found a mean +/- standard deviation (SD) value of 75.79 +/- 15.3 with 3D-HCT and 77.4 +/- 17.17 with IVU, which were not statistically significant. For ID (in mm) we found a mean +/- SD value of 7.5 +/- 2.92 with 3D-HCT and 8.15 +/- 3.27 with IVU. For CD we found a mean +/- SD value of 2.37 +/- 0.75 calices with 3D-HCT and 2.43 +/- 0.67 calices with IVU. On analyzing the difference between 3D-HCT and IVU, we found a mean +/- SD value of 0.06 +/- 0.51, and we verified that 74.5% of the examinations compared did not present statistically significant difference, with a Wilcoxon p-value of 0.405. Although 3D-HCT is more precise to study calculus location, tumors, and vessels, IVU was also demonstrated to be as precise as 3D-HCT for studying the lower pole spatial anatomy. We did not observe any statistically significant difference in the measurements of IPA, ID, and CD obtained using 3D-HCT when compared with those obtained using IVU. Therefore, 3D-HCT does not present any advantage over IVU in the evaluation of lower pole caliceal anatomy.

  13. Three-dimensional computed tomography-guided monotherapeutic pararectal brachytherapy of prostate cancer with seminal vesicle invasion

    International Nuclear Information System (INIS)

    Koutrouvelis, Panos; Lailas, Niko; Hendricks, Fred; Gil-Montero, Guillermo; Sehn, James; Katz, Stuart

    2001-01-01

    Purpose: To treat patients with prostate cancer and seminal vesicle invasion with monotherapeutic three dimensional computed tomography (3-DCT)-guided posterior pararectal brachytherapy. Methods and materials: Three hundred and sixty two patients with clinical stage T1 a,b or T2 a,b of prostate cancer were referred for 3-DCT-guided brachytherapy. Each underwent further staging with 3-D CT-guided pararectal biopsy of the seminal vesicles under local anesthesia during the pre-treatment CT-planning. Forty-three patients (12%) were upstaged to T3 cNoMo disease. In the set of 43 patients, Eight had Gleason's score≤6, 24 Gleason's score=7, and 11 patients ≥8. Initial PSA was 20 in 18 patients. Of the 43 patients, 37 patients were treated monotherapeutically with 3-D CT-guided brachytherapy. No patients received hormone therapy after the implant. The prescribed dosage to the seminal vesicles and prostate is 120 Gy with Pd-103 seeds and 144 Gy with 1-125 seeds. Results: The prescribed dosage was achieved in all 37 patient's throughout the seminal vesicles whose range of target radiation extended 5-10 mm outside the target in the adjacent fat as calculated with post-implant CT-dosimetry with Varian Brachy Vision or MMS software. Prostate Specific Antigen (PSA) outcome data were available in 34 patients treated with monotherapy and follow up ranged from 12-56 months (median, 24 months). Decreased PSA levels were stratified into six groups based on the presenting Gleason's score and initial PSA. In the first group (with Gleason's score≤6 and initial PSA 20 ng/ml), PSA decreased to less than 0.5 ng/ml in four out of eight patients (50%). All of the patients in the fourth group (with Gleason's score≥8 and initial PSA 20 ng/ml). There were no patients with Gleason's score of 1-6 and greater than 20 ng/ml initial PSA. Patients, irrespective of the Gleason's score and PSA, had an overall response of decreased PSA (less than 1 ng/ml) of 79%. Conclusion: 3-D CT

  14. Multicenter study of quantitative computed tomography analysis using a computer-aided three-dimensional system in patients with idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Iwasawa, Tae; Kanauchi, Tetsu; Hoshi, Toshiko; Ogura, Takashi; Baba, Tomohisa; Gotoh, Toshiyuki; Oba, Mari S

    2016-01-01

    To evaluate the feasibility of automated quantitative analysis with a three-dimensional (3D) computer-aided system (i.e., Gaussian histogram normalized correlation, GHNC) of computed tomography (CT) images from different scanners. Each institution's review board approved the research protocol. Informed patient consent was not required. The participants in this multicenter prospective study were 80 patients (65 men, 15 women) with idiopathic pulmonary fibrosis. Their mean age was 70.6 years. Computed tomography (CT) images were obtained by four different scanners set at different exposures. We measured the extent of fibrosis using GHNC, and used Pearson's correlation analysis, Bland-Altman plots, and kappa analysis to directly compare the GHNC results with manual scoring by radiologists. Multiple linear regression analysis was performed to determine the association between the CT data and forced vital capacity (FVC). For each scanner, the extent of fibrosis as determined by GHNC was significantly correlated with the radiologists' score. In multivariate analysis, the extent of fibrosis as determined by GHNC was significantly correlated with FVC (p < 0.001). There was no significant difference between the results obtained using different CT scanners. Gaussian histogram normalized correlation was feasible, irrespective of the type of CT scanner used.

  15. Three-dimensional evaluation of pharyngeal airway in individuals with varying growth patterns using cone beam computed tomography

    OpenAIRE

    Rohan Diwakar; Maninder Singh Sidhu; Mona Prabhakar; Seema Grover; Ritu Phogat

    2015-01-01

    Introduction: The purpose of this study was to evaluate the pharyngeal airway volume in individuals with different vertical growth patterns. Methods: Cone beam computed tomography scans were evaluated of 40 subjects with the age range from 14 to 25 years and were divided into three groups. Horizontal growers consisted of 13 subjects, normal growers consisted of 14 subjects, and the vertical growers consisted of 13 subjects. The pharyngeal airway volume was measured using In Vivo Dental 5.1 so...

  16. Three-dimensional computer graphics-based ankle morphometry with computerized tomography for total ankle replacement design and positioning.

    Science.gov (United States)

    Kuo, Chien-Chung; Lu, Hsuan-Lun; Leardini, Alberto; Lu, Tung-Wu; Kuo, Mei-Ying; Hsu, Horng-Chaung

    2014-05-01

    Morphometry of the bones of the ankle joint is important for the design of joint replacements and their surgical implantations. However, very little three-dimensional (3D) data are available and not a single study has addressed the Chinese population. Fifty-eight fresh frozen Chinese cadaveric ankle specimens, 26 females, and 32 males, were CT-scanned in the neutral position and their 3D computer graphics-based models were reconstructed. The 3D morphology of the distal tibia/fibula segment and the full talus was analyzed by measuring 31 parameters, defining the relevant dimensions, areas, and volumes from the models. The measurements were compared statistically between sexes and with previously reported data from Caucasian subjects. The results showed that, within a general similarity of ankle morphology between the current Chinese and previous Caucasian subjects groups, there were significant differences in 9 out of the 31 parameters analyzed. From a quantitative comparison with available prostheses designed for the Caucasian population, few of these designs have both tibial and talar components suitable in dimension for the Chinese population. The current data will be helpful for the sizing, design, and surgical positioning of ankle replacements and for surgical instruments, especially for the Chinese population. Copyright © 2013 Wiley Periodicals, Inc.

  17. An unusual case of thoracic ectopia cordis in a Toggenburg Goat and its three-dimensional images constructed with X-ray computed tomography.

    Science.gov (United States)

    Lai, Jyh-Mirn; Wu, Jui-Te; Yang, Wei-Cheng; Chao, Ming-Hsin; Nagahata, Hajime

    2016-05-01

    A two-day-old female Toggenburg goat with thoracic ectopia cordis (EC) was diagnosed via radiography and computed tomography. The goat was born with EC, defects of the sternum and a supra-umbilical abdominal wall, but without the presence of Cantrell's syndrome. Necropsy and histopathological findings indicated the affected kid had malformation of the heart with an enlarged left ventricle. The findings showed the heart (9 x 5 x 5 cm) stayed outside the thorax, and was covered by a semitransparent membrane. This report is the first to describe a case of thoracic EC in a goat whose sternum was not developed fully and was not connected to the ribs. It is also the first paper to describe three-dimensional images of this condition constructed from computed tomography scans.

  18. Comparison of two three-dimensional cephalometric analysis computer software

    OpenAIRE

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-01-01

    Background: Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Materials and Methods: Twenty cone beam computed tomography images were obtained using i-CAT® imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (Unive...

  19. Three-dimensional SPECT [single photon emission computed tomography] reconstruction of combined cone beam and parallel beam data

    International Nuclear Information System (INIS)

    Jaszczak, R.J.; Jianying Li; Huili Wang; Coleman, R.E.

    1992-01-01

    Single photon emission computed tomography (SPECT) using cone beam (CB) collimation exhibits increased sensitivity compared with acquisition geometries using parallel (P) hole collimation. However, CB collimation has a smaller field-of-view which may result in truncated projections and image artifacts. A primary objective of this work is to investigate maximum likelihood-expectation maximization (ML-EM) methods to reconstruct simultaneously acquired parallel and cone beam (P and CB) SPECT data. Simultaneous P and CB acquisition can be performed with commercially available triple camera systems by using two cone-beam collimators and a single parallel-hole collimator. The loss in overall sensitivity (relative to the use of three CB collimators) is about 15 to 20%. The authors have developed three methods to combine P and CB data using modified ML-EM algorithms. (author)

  20. Do three-dimensional reconstructions add to the diagnostic value of computed tomography in the field of traumatology?

    International Nuclear Information System (INIS)

    Billet, F.P.J.; Schmitt, W.G.H.; Hofmann, M.; Huber, M.; Gay, B.

    1990-01-01

    Very little time was needed for three-dimensional techniques to show that they are of great importance to the accurracy and, above all, interpretation of CT-based diagnostic findings in the skeleton. This method is not associated with any increased risks from radiation and if there is no absolute requirement for a 'second plane' to be displayed, as for instance in fractures of the calcaneus, radiation exposure can be reduced even further. Particular mention should here also be made of the sternoclavicular joint, coracoid process and intervertebral foramina, even more so as we feel that the diagnostic advantages offered by three-dimensional techniques in traumatology have so far not been described in sufficient detail. (orig./GDG) [de

  1. The value of three-dimensional helical computed tomography for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2016-03-01

    Full Text Available Objective: The aim of our study was to determine if there is any advantage of three-dimensional helical computed tomography (3D-HCT over intravenous urogram (IVU for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones. Methods: From June 2012 to January 2014, a total of 52 cases of lower pole renal stones underwent retrograde intrarenal surgery (RIRS in our center. All patients underwent a preoperative IVU and three-dimensional helical computed tomography urography (3D-CTU program to define the collecting system anatomy, manly concerning the following lower pole features; infundibu-lopelvic angle (IPA, infundibular length (IL, and infundibular width (IW. The examinations were performed in the same center of reference with a standardized method and with 3D-HCT Siemens Somaton Plus equipment. The measurements were performed by the same researcher, using a ruler and a square. Results: Based on clinical threshold difference of the anatomic factors on an IVU image to compare the difference between an IVU image and a 3D-CT image of 52 patients, the IPA was <30° when measured on intravenous pyelography (IVP for 21 patients. We found that with the IPA of <30° measured with IVP only 19% (4/21 were correctly classified in the same size category using 3D-HCT, whereas 81% (17/21 were upgraded to 40–50° on 3D-CT. This difference was significant between IVP and 3D-HCT. Conclusions: 3D-HCT has advantages over IVU when analyzing the morphometric and the morphological features of kidney lower pole spatial anatomy for the retrograde flexible ureteronephroscopy in the treatment of lower pole calyx stones. Keywords: Intravenous urogram, Computed tomography urography, Flexible ureterorenoscopy, Lower pole, Renal stones

  2. Three-dimensional analysis of rodent paranasal sinus cavities from X-ray computed tomography (CT) scans

    Science.gov (United States)

    Phillips, Jonathan E.; Ji, Lunan; Rivelli, Maria A.; Chapman, Richard W.; Corboz, Michel R.

    2009-01-01

    Continuous isometric microfocal X-ray computed tomography (CT) scans were acquired from an AKR/J mouse, Brown-Norway rat, and Hartley guinea pig. The anatomy and volume of the paranasal sinus cavities were defined from 2-dimensional (2-D) and 3-dimensional (3-D) CT images. Realistic 3-D images were reconstructed and used to determine the anterior maxillary, posterior maxillary, and ethmoid sinus cavity airspace volumes (mouse: 0.6, 0.7, and 0.7 mm3, rat: 8.6, 7.7, and 7.0 mm3, guinea pig: 63.5, 46.6 mm3, and no ethmoid cavity, respectively). The mouse paranasal sinus cavities are similar to the corresponding rat cavities, with a reduction in size, while the corresponding maxillary sinus cavities in the guinea pig are different in size, location, and architecture. Also, the ethmoid sinus cavity is connected by a common drainage pathway to the posterior maxillary sinus in mouse and rat while a similar ethmoid sinus was not present in the guinea pig. We conclude that paranasal sinus cavity airspace opacity (2-D) or volume (3-D) determined by micro-CT scanning may be used to conduct longitudinal studies on the patency of the maxillary sinus cavities of rodents. This represents a potentially useful endpoint for developing and testing drugs in a small animal model of sinusitis. PMID:19794893

  3. [Three-dimensional evaluation of condylar morphology remodeling after orthognathic surgery in mandibular retrognathism by cone-beam computed tomography].

    Science.gov (United States)

    Chen, Shuo; Liu, Xiao-jing; Li, Zi-li; Liang, Cheng; Wang, Xiao-xia; Fu, Kai-yuan; Yi, Biao

    2015-08-18

    To evaluate the effect of orthognathic surgery on condylar morphology changes by comparing three-dimension surface reconstructions of condyles using cone-beam computed tomography (CBCT) data. In the study, 18 patients with mandible retrognathism deformities were included and CBCT data of 36 temporomandibular joints were collected before surgery and 12 months after surgery. Condyles were reconstructed and superimposed pre- and post-operatively to compare the changes of condylar surfaces. One-sample t test and χ2 test were performed for the analysis of three-dimension metric measurement and condylar head remodeling signs. P<0.05 was considered significant. The root-mean-square (RMS) of condylar surface changes before and after the surgery was (0.37±0.11) mm, which was significant statistically (P<0.05). The distribution of condylar remodeling signs showed significant difference (P<0.05). Bone resorption occurred predominantly in the posterior area of condylar head and bone formation occurred mainly in the anterior area. Three-dimension superimposition method based on CBCT data showed that condylar morphology had undergone remodeling after mandibular advancement.

  4. Three-dimensional in vivo imaging of the murine liver: a micro-computed tomography-based anatomical study.

    Directory of Open Access Journals (Sweden)

    Teresa Fiebig

    Full Text Available Various murine models are currently used to study acute and chronic pathological processes of the liver, and the efficacy of novel therapeutic regimens. The increasing availability of high-resolution small animal imaging modalities presents researchers with the opportunity to precisely identify and describe pathological processes of the liver. To meet the demands, the objective of this study was to provide a three-dimensional illustration of the macroscopic anatomical location of the murine liver lobes and hepatic vessels using small animal imaging modalities. We analysed micro-CT images of the murine liver by integrating additional information from the published literature to develop comprehensive illustrations of the macroscopic anatomical features of the murine liver and hepatic vasculature. As a result, we provide updated three-dimensional illustrations of the macroscopic anatomy of the murine liver and hepatic vessels using micro-CT. The information presented here provides researchers working in the field of experimental liver disease with a comprehensive, easily accessable overview of the macroscopic anatomy of the murine liver.

  5. Three-dimensional evaluation of human jaw bone microarchitecture: correlation between the microarchitectural parameters of cone beam computed tomography and micro-computer tomography.

    Science.gov (United States)

    Kim, Jo-Eun; Yi, Won-Jin; Heo, Min-Suk; Lee, Sam-Sun; Choi, Soon-Chul; Huh, Kyung-Hoe

    2015-12-01

    To evaluate the potential feasibility of cone beam computed tomography (CBCT) in the assessment of trabecular bone microarchitecture. Sixty-eight specimens from four pairs of human jaw were scanned using both micro-computed tomography (micro-CT) of 19.37-μm voxel size and CBCT of 100-μm voxel size. The correlation of 3-dimensional parameters between CBCT and micro-CT was evaluated. All parameters, except bone-specific surface and trabecular thickness, showed linear correlations between the 2 imaging modalities (P < .05). Among the parameters, bone volume, percent bone volume, trabecular separation, and degree of anisotropy (DA) of CBCT images showed strong correlations with those of micro-CT images. DA showed the strongest correlation (r = 0.693). Most microarchitectural parameters from CBCT were correlated with those from micro-CT. Some microarchitectural parameters, especially DA, could be used as strong predictors of bone quality in the human jaw. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lang, P.; Genant, H.K.

    1988-01-07

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

  7. Evaluation of Orthopedic Metal Artifact Reduction Application in Three-Dimensional Computed Tomography Reconstruction of Spinal Instrumentation: A Single Saudi Center Experience.

    Science.gov (United States)

    Ali, Amir Monir

    2018-01-01

    The aim of the study was to evaluate the commercially available orthopedic metal artifact reduction (OMAR) technique in postoperative three-dimensional computed tomography (3DCT) reconstruction studies after spinal instrumentation and to investigate its clinical application. One hundred and twenty (120) patients with spinal metallic implants were included in the study. All had 3DCT reconstruction examinations using the OMAR software after obtaining the informed consents and approval of the Institution Ethical Committee. The degree of the artifacts, the related muscular density, the clearness of intermuscular fat planes, and definition of the adjacent vertebrae were qualitatively evaluated. The diagnostic satisfaction and quality of the 3D reconstruction images were thoroughly assessed. The majority (96.7%) of 3DCT reconstruction images performed were considered satisfactory to excellent for diagnosis. Only 3.3% of the reconstructed images had rendered unacceptable diagnostic quality. OMAR can effectively reduce metallic artifacts in patients with spinal instrumentation with highly diagnostic 3DCT reconstruction images.

  8. Generation of realistic virtual nodules based on three-dimensional spatial resolution in lung computed tomography: A pilot phantom study.

    Science.gov (United States)

    Narita, Akihiro; Ohkubo, Masaki; Murao, Kohei; Matsumoto, Toru; Wada, Shinichi

    2017-10-01

    The aim of this feasibility study using phantoms was to propose a novel method for obtaining computer-generated realistic virtual nodules in lung computed tomography (CT). In the proposed methodology, pulmonary nodule images obtained with a CT scanner are deconvolved with the point spread function (PSF) in the scan plane and slice sensitivity profile (SSP) measured for the scanner; the resultant images are referred to as nodule-like object functions. Next, by convolving the nodule-like object function with the PSF and SSP of another (target) scanner, the virtual nodule can be generated so that it has the characteristics of the spatial resolution of the target scanner. To validate the methodology, the authors applied physical nodules of 5-, 7- and 10-mm-diameter (uniform spheres) included in a commercial CT test phantom. The nodule-like object functions were calculated from the sphere images obtained with two scanners (Scanner A and Scanner B); these functions were referred to as nodule-like object functions A and B, respectively. From these, virtual nodules were generated based on the spatial resolution of another scanner (Scanner C). By investigating the agreement of the virtual nodules generated from the nodule-like object functions A and B, the equivalence of the nodule-like object functions obtained from different scanners could be assessed. In addition, these virtual nodules were compared with the real (true) sphere images obtained with Scanner C. As a practical validation, five types of laboratory-made physical nodules with various complicated shapes and heterogeneous densities, similar to real lesions, were used. The nodule-like object functions were calculated from the images of these laboratory-made nodules obtained with Scanner A. From them, virtual nodules were generated based on the spatial resolution of Scanner C and compared with the real images of laboratory-made nodules obtained with Scanner C. Good agreement of the virtual nodules generated from

  9. Three-dimensional lung tumor segmentation from x-ray computed tomography using sparse field active models.

    Science.gov (United States)

    Awad, Joseph; Owrangi, Amir; Villemaire, Lauren; O'Riordan, Elaine; Parraga, Grace; Fenster, Aaron

    2012-02-01

    Manual segmentation of lung tumors is observer dependent and time-consuming but an important component of radiology and radiation oncology workflow. The objective of this study was to generate an automated lung tumor measurement tool for segmentation of pulmonary metastatic tumors from x-ray computed tomography (CT) images to improve reproducibility and decrease the time required to segment tumor boundaries. The authors developed an automated lung tumor segmentation algorithm for volumetric image analysis of chest CT images using shape constrained Otsu multithresholding (SCOMT) and sparse field active surface (SFAS) algorithms. The observer was required to select the tumor center and the SCOMT algorithm subsequently created an initial surface that was deformed using level set SFAS to minimize the total energy consisting of mean separation, edge, partial volume, rolling, distribution, background, shape, volume, smoothness, and curvature energies. The proposed segmentation algorithm was compared to manual segmentation whereby 21 tumors were evaluated using one-dimensional (1D) response evaluation criteria in solid tumors (RECIST), two-dimensional (2D) World Health Organization (WHO), and 3D volume measurements. Linear regression goodness-of-fit measures (r(2) = 0.63, p < 0.0001; r(2) = 0.87, p < 0.0001; and r(2) = 0.96, p < 0.0001), and Pearson correlation coefficients (r = 0.79, p < 0.0001; r = 0.93, p < 0.0001; and r = 0.98, p < 0.0001) for 1D, 2D, and 3D measurements, respectively, showed significant correlations between manual and algorithm results. Intra-observer intraclass correlation coefficients (ICC) demonstrated high reproducibility for algorithm (0.989-0.995, 0.996-0.997, and 0.999-0.999) and manual measurements (0.975-0.993, 0.985-0.993, and 0.980-0.992) for 1D, 2D, and 3D measurements, respectively. The intra-observer coefficient of variation (CV%) was low for algorithm (3.09%-4.67%, 4.85%-5.84%, and 5

  10. Computational methods for three-dimensional microscopy reconstruction

    CERN Document Server

    Frank, Joachim

    2014-01-01

    Approaches to the recovery of three-dimensional information on a biological object, which are often formulated or implemented initially in an intuitive way, are concisely described here based on physical models of the object and the image-formation process. Both three-dimensional electron microscopy and X-ray tomography can be captured in the same mathematical framework, leading to closely-related computational approaches, but the methodologies differ in detail and hence pose different challenges. The editors of this volume, Gabor T. Herman and Joachim Frank, are experts in the respective methodologies and present research at the forefront of biological imaging and structural biology.   Computational Methods for Three-Dimensional Microscopy Reconstruction will serve as a useful resource for scholars interested in the development of computational methods for structural biology and cell biology, particularly in the area of 3D imaging and modeling.

  11. Three-dimensional cone-beam computed tomography: A new approach to the diagnosis and treatment planning of impacted mandibular third molars

    International Nuclear Information System (INIS)

    Kanazirska, P.; Yordanov, G.; Angelova, I.; Kanazirski, N.

    2017-01-01

    Cone Beam Computed Tomography (CBCT) is a relatively new method in dental practice which raises a more precise diagnosis and correct treatment plan. The image of the impacted teeth and surrounding structures with CBCT are with better quality and informativity than the conventional imaging-diagnostic methods . The use of CBCT to determine the ratio of the impacted teeth to the mandibular canal is necessary for the prevention of complications associated with iatrogenic trauma to the vascular- nerve bundle. The aim of this study was to determine the anatomic relationship between the roots of impacted third molars and mandibular canal using CBCT imaging. The studied patients with impacted third molars of the mandible are 127, aged 17 through 60.They were examined with Cone-beam Computed Tomography (CBCT). From the 195 impacted third molar with the - higher frequency are those in which the channel is below their roots-107 teeth (54.9%). The second frequency are the teeth where the channel is located lingually-57 (29.2%). Follow the teeth, in which the channel has a buccal location-25 (12.8%). With the lowest frequency are cases in which the mandibular canal is between the roots of impacted teeth-6 teeth (3.1%).At 132 teeth (67.7%) mandibular canal is at a distance of 1 mm. At 63 teeth (32.3%) the channel is at a distance of over 1 mm. The high resolution cuts in different planes and three-dimensional reconstructions made substantially as set forth preferred for different specialists in dentistry. Precise measurements of the bone around the mandibular canal prevent damage to neurovascular bundle. This makes the method preferred for planning appropriate treatment. Key words: Cone Beam Computed Tomography. Impacted Third Molars. Mandibular Canal [bg

  12. Implementation of a computationally efficient least-squares algorithm for highly under-determined three-dimensional diffuse optical tomography problems.

    Science.gov (United States)

    Yalavarthy, Phaneendra K; Lynch, Daniel R; Pogue, Brian W; Dehghani, Hamid; Paulsen, Keith D

    2008-05-01

    Three-dimensional (3D) diffuse optical tomography is known to be a nonlinear, ill-posed and sometimes under-determined problem, where regularization is added to the minimization to allow convergence to a unique solution. In this work, a generalized least-squares (GLS) minimization method was implemented, which employs weight matrices for both data-model misfit and optical properties to include their variances and covariances, using a computationally efficient scheme. This allows inversion of a matrix that is of a dimension dictated by the number of measurements, instead of by the number of imaging parameters. This increases the computation speed up to four times per iteration in most of the under-determined 3D imaging problems. An analytic derivation, using the Sherman-Morrison-Woodbury identity, is shown for this efficient alternative form and it is proven to be equivalent, not only analytically, but also numerically. Equivalent alternative forms for other minimization methods, like Levenberg-Marquardt (LM) and Tikhonov, are also derived. Three-dimensional reconstruction results indicate that the poor recovery of quantitatively accurate values in 3D optical images can also be a characteristic of the reconstruction algorithm, along with the target size. Interestingly, usage of GLS reconstruction methods reduces error in the periphery of the image, as expected, and improves by 20% the ability to quantify local interior regions in terms of the recovered optical contrast, as compared to LM methods. Characterization of detector photo-multiplier tubes noise has enabled the use of the GLS method for reconstructing experimental data and showed a promise for better quantification of target in 3D optical imaging. Use of these new alternative forms becomes effective when the ratio of the number of imaging property parameters exceeds the number of measurements by a factor greater than 2.

  13. Three-Dimensional Image Fusion of 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography and Contrast-Enhanced Computed Tomography for Computer-Assisted Planning of Maxillectomy of Recurrent Maxillary Squamous Cell Carcinoma and Defect Reconstruction.

    Science.gov (United States)

    Yu, Yao; Zhang, Wen-Bo; Liu, Xiao-Jing; Guo, Chuan-Bin; Yu, Guang-Yan; Peng, Xin

    2017-06-01

    The purpose of this study was to describe new technology assisted by 3-dimensional (3D) image fusion of 18 F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT (CECT) for computer planning of a maxillectomy of recurrent maxillary squamous cell carcinoma and defect reconstruction. Treatment of recurrent maxillary squamous cell carcinoma usually includes tumor resection and free flap reconstruction. FDG-PET/CT provided images of regions of abnormal glucose uptake and thus showed metabolic tumor volume to guide tumor resection. CECT data were used to create 3D reconstructed images of vessels to show the vascular diameters and locations, so that the most suitable vein and artery could be selected during anastomosis of the free flap. The data from preoperative maxillofacial CECT scans and FDG-PET/CT imaging were imported into the navigation system (iPlan 3.0; Brainlab, Feldkirchen, Germany). Three-dimensional image fusion between FDG-PET/CT and CECT was accomplished using Brainlab software according to the position of the 2 skulls simulated in the CECT image and PET/CT image, respectively. After verification of the image fusion accuracy, the 3D reconstruction images of the metabolic tumor, vessels, and other critical structures could be visualized within the same coordinate system. These sagittal, coronal, axial, and 3D reconstruction images were used to determine the virtual osteotomy sites and reconstruction plan, which was provided to the surgeon and used for surgical navigation. The average shift of the 3D image fusion between FDG-PET/CT and CECT was less than 1 mm. This technique, by clearly showing the metabolic tumor volume and the most suitable vessels for anastomosis, facilitated resection and reconstruction of recurrent maxillary squamous cell carcinoma. We used 3D image fusion of FDG-PET/CT and CECT to successfully accomplish resection and reconstruction of recurrent maxillary squamous cell carcinoma

  14. Resolving the three-dimensional microstructure of polymer electrolyte fuel cell electrodes using nanometer-scale X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Epting, William K.; Gelb, Jeff; Litster, Shawn

    2012-02-08

    The electrodes of a polymer electrolyte fuel cell (PEFC) are composite porous layers consisting of carbon and platinum nanoparticles and a polymer electrolyte binder. The proper composition and arrangement of these materials for fast reactant transport and high electrochemical activity is crucial to achieving high performance, long lifetimes, and low costs. Here, the microstructure of a PEFC electrode using nanometer-scale X-ray computed tomography (nano-CT) with a resolution of 50 nm is investigated. The nano-CT instrument obtains this resolution for the low-atomic-number catalyst support and binder using a combination of a Fresnel zone plate objective and Zernike phase contrast imaging. High-resolution, non-destructive imaging of the three-dimensional (3D) microstructures provides important new information on the size and form of the catalyst particle agglomerates and pore spaces. Transmission electron microscopy (TEM) and mercury intrusion porosimetry (MIP) is applied to evaluate the limits of the resolution and to verify the 3D reconstructions. The computational reconstructions and size distributions obtained with nano-CT can be used for evaluating electrode preparation, performing pore-scale simulations, and extracting effective morphological parameters for large-scale computational models. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Customized Computed Tomography-Based Boost Volumes in Breast-Conserving Therapy: Use of Three-Dimensional Histologic Information for Clinical Target Volume Margins

    International Nuclear Information System (INIS)

    Hanbeukers, Bianca; Borger, Jacques; Ende, Piet van den; Ent, Fred van der; Houben, Ruud; Jager, Jos; Keymeulen, Kristien; Murrer, Lars; Sastrowijoto, Suprapto; Vijver, Koen van de; Boersma, Liesbeth

    2009-01-01

    Purpose: To determine the difference in size between computed tomography (CT)-based irradiated boost volumes and simulator-based irradiated volumes in patients treated with breast-conserving therapy and to analyze whether the use of anisotropic three-dimensional clinical target volume (CTV) margins using the histologically determined free resection margins allows for a significant reduction of the CT-based boost volumes. Patients and Methods: The CT data from 49 patients were used to delineate a planning target volume (PTV) with isotropic CTV margins and to delineate a PTV sim that mimicked the PTV as delineated in the era of conventional simulation. For 17 patients, a PTV with anisotropic CTV margins was defined by applying customized three-dimensional CTV margins, according to the free excision margins in six directions. Boost treatment plans consisted of conformal portals for the CT-based PTVs and rectangular fields for the PTV sim . Results: The irradiated volume (volume receiving ≥95% of the prescribed dose [V 95 ]) for the PTV with isotropic CTV margins was 1.6 times greater than that for the PTV sim : 228 cm 3 vs. 147 cm 3 (p 95 was similar to the V 95 for the PTV sim (190 cm 3 vs. 162 cm 3 ; p = NS). The main determinant for the irradiated volume was the size of the excision cavity (p < .001), which was mainly related to the interval between surgery and the planning CT scan (p = .029). Conclusion: CT-based PTVs with isotropic margins for the CTV yield much greater irradiated volumes than fluoroscopically based PTVs. Applying individualized anisotropic CTV margins allowed for a significant reduction of the irradiated boost volume.

  16. Proposal of new classification of femoral trochanteric fracture by three-dimensional computed tomography and relationship to usual plain X-ray classification.

    Science.gov (United States)

    Shoda, Etsuo; Kitada, Shimpei; Sasaki, Yu; Hirase, Hitoshi; Niikura, Takahiro; Lee, Sang Yang; Sakurai, Atsushi; Oe, Keisuke; Sasaki, Takeharu

    2017-01-01

    Classification of femoral trochanteric fractures is usually based on plain X-ray findings using the Evans, Jensen, or AO/OTA classification. However, complications such as nonunion and cut out of the lag screw or blade are seen even in stable fracture. This may be due to the difficulty of exact diagnosis of fracture pattern in plain X-ray. Computed tomography (CT) may provide more information about the fracture pattern, but such data are scarce. In the present study, it was performed to propose a classification system for femoral trochanteric fractures using three-dimensional CT (3D-CT) and investigate the relationship between this classification and conventional plain X-ray classification. Using three-dimensional (3D)-CT, fractures were classified as two, three, or four parts using combinations of the head, greater trochanter, lesser trochanter, and shaft. We identified five subgroups of three-part fractures according to the fracture pattern involving the greater and lesser trochanters. In total, 239 femoral trochanteric fractures (45 men, 194 women; average age, 84.4 years) treated in four hospitals were classified using our 3D-CT classification. The relationship between this 3D-CT classification and the AO/OTA, Evans, and Jensen X-ray classifications was investigated. In the 3D-CT classification, many fractures exhibited a large oblique fragment of the greater trochanter including the lesser trochanter. This fracture type was recognized as unstable in the 3D-CT classification but was often classified as stable in each X-ray classification. It is difficult to evaluate fracture patterns involving the greater trochanter, especially large oblique fragments including the lesser trochanter, using plain X-rays. The 3D-CT shows the fracture line very clearly, making it easy to classify the fracture pattern.

  17. On-Line Use of Three-Dimensional Marker Trajectory Estimation From Cone-Beam Computed Tomography Projections for Precise Setup in Radiotherapy for Targets With Respiratory Motion

    International Nuclear Information System (INIS)

    Worm, Esben S.; Høyer, Morten; Fledelius, Walther; Nielsen, Jens E.; Larsen, Lars P.; Poulsen, Per R.

    2012-01-01

    Purpose: To develop and evaluate accurate and objective on-line patient setup based on a novel semiautomatic technique in which three-dimensional marker trajectories were estimated from two-dimensional cone-beam computed tomography (CBCT) projections. Methods and Materials: Seven treatment courses of stereotactic body radiotherapy for liver tumors were delivered in 21 fractions in total to 6 patients by a linear accelerator. Each patient had two to three gold markers implanted close to the tumors. Before treatment, a CBCT scan with approximately 675 two-dimensional projections was acquired during a full gantry rotation. The marker positions were segmented in each projection. From this, the three-dimensional marker trajectories were estimated using a probability based method. The required couch shifts for patient setup were calculated from the mean marker positions along the trajectories. A motion phantom moving with known tumor trajectories was used to examine the accuracy of the method. Trajectory-based setup was retrospectively used off-line for the first five treatment courses (15 fractions) and on-line for the last two treatment courses (6 fractions). Automatic marker segmentation was compared with manual segmentation. The trajectory-based setup was compared with setup based on conventional CBCT guidance on the markers (first 15 fractions). Results: Phantom measurements showed that trajectory-based estimation of the mean marker position was accurate within 0.3 mm. The on-line trajectory-based patient setup was performed within approximately 5 minutes. The automatic marker segmentation agreed with manual segmentation within 0.36 ± 0.50 pixels (mean ± SD; pixel size, 0.26 mm in isocenter). The accuracy of conventional volumetric CBCT guidance was compromised by motion smearing (≤21 mm) that induced an absolute three-dimensional setup error of 1.6 ± 0.9 mm (maximum, 3.2) relative to trajectory-based setup. Conclusions: The first on-line clinical use of

  18. Three-Dimensional Computer Graphics Brain-Mapping Project

    Science.gov (United States)

    1988-03-24

    1975-76, one of these brains was hand digitized. It was then reconstructed three dimensionally, using an Evans and Sutherland Picture System 2. This...Yakovlev Collection, we use the Evans and Sutherland Picture System 2 which we have been employing for this purpose for a dozen years. Its virtue is...careful, experimentally designed new protocol (See Figure 20). Most of these heads were imaged with Computed Tomography, thanks to Clint Stiles of Picker

  19. Three dimensional time reversal optical tomography

    Science.gov (United States)

    Wu, Binlin; Cai, W.; Alrubaiee, M.; Xu, M.; Gayen, S. K.

    2011-03-01

    Time reversal optical tomography (TROT) approach is used to detect and locate absorptive targets embedded in a highly scattering turbid medium to assess its potential in breast cancer detection. TROT experimental arrangement uses multi-source probing and multi-detector signal acquisition and Multiple-Signal-Classification (MUSIC) algorithm for target location retrieval. Light transport from multiple sources through the intervening medium with embedded targets to the detectors is represented by a response matrix constructed using experimental data. A TR matrix is formed by multiplying the response matrix by its transpose. The eigenvectors with leading non-zero eigenvalues of the TR matrix correspond to embedded objects. The approach was used to: (a) obtain the location and spatial resolution of an absorptive target as a function of its axial position between the source and detector planes; and (b) study variation in spatial resolution of two targets at the same axial position but different lateral positions. The target(s) were glass sphere(s) of diameter ~9 mm filled with ink (absorber) embedded in a 60 mm-thick slab of Intralipid-20% suspension in water with an absorption coefficient μa ~ 0.003 mm-1 and a transport mean free path lt ~ 1 mm at 790 nm, which emulate the average values of those parameters for human breast tissue. The spatial resolution and accuracy of target location depended on axial position, and target contrast relative to the background. Both the targets could be resolved and located even when they were only 4-mm apart. The TROT approach is fast, accurate, and has the potential to be useful in breast cancer detection and localization.

  20. The location of midfacial landmarks according to the method of establishing the midsagittal reference plane in three-dimensional computed tomography analysis of facial asymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Sun; Lee, Eun Joo; Lee, Jae Seo; Kang, Byung Cheock; Yoon, Suk Ja [Dental Science Research Institute, Chonnam National University, Gwangju (Korea, Republic of); Song, In Ja [Dept. of Nursing, Kwangju Women' s University, Gwangju (Korea, Republic of)

    2015-12-15

    The purpose of this study was to evaluate the influence of methods of establishing the midsagittal reference plane (MRP) on the locations of midfacial landmarks in the three-dimensional computed tomography (CT) analysis of facial asymmetry. A total of 24 patients (12 male and 12 female; mean age, 22.5 years; age range, 18.2-29.7 years) with facial asymmetry were included in this study. The MRP was established using two different methods on each patient's CT image. The x-coordinates of four midfacial landmarks (the menton, nasion, upper incisor, and lower incisor) were obtained by measuring the distance and direction of the landmarks from the MRP, and the two methods were compared statistically. The direction of deviation and the severity of asymmetry found using each method were also compared. The x-coordinates of the four anatomic landmarks all showed a statistically significant difference between the two methods of establishing the MRP. For the nasion and lower incisor, six patients (25.0%) showed a change in the direction of deviation. The severity of asymmetry also changed in 16 patients (66.7%). The results of this study suggest that the locations of midfacial landmarks change significantly according to the method used to establish the MRP.

  1. Maxillary distraction osteogenesis in the adolescent cleft patient: three-dimensional computed tomography analysis of linear and volumetric changes over five years.

    Science.gov (United States)

    Chen, Philip Kuo-Ting; Por, Yong-Chen; Liou, Eric Jein-Wein; Chang, Frank Chun-Shin

    2011-07-01

    To assess the results of maxillary distraction osteogenesis with the Rigid External Distraction System using three-dimensional computed tomography scan volume-rendered images with respect to stability and facial growth at three time frames: preoperative (T0), 1-year postoperative (T1), and 5-years postoperative (T2). Retrospective analysis. Tertiary. A total of 12 patients with severe cleft maxillary hypoplasia were treated between June 30, 1997, and July 15, 1998. The mean age at surgery was 11 years 1 month. Le Fort I maxillary distraction osteogenesis. Distraction was started 2 to 5 days postsurgery at a rate of 1 mm per day. The consolidation period was 3 months. No face mask was used. A paired t test was used for statistical analysis. Overjet, ANB, and SNA and maxillary, pterygoid, and mandibular volumes. From T0 to T1, there were statistically significant increments of overjet, ANB, and SNA and maxillary, pterygoid, and mandibular volumes. The T1 to T2 period demonstrated a reduction of overjet (30.07%) and ANB (54.42%). The maxilla showed a stable SNA and a small but statistically significant advancement of the ANS point. There was a significant increase in the mandibular volume. However, there was no significant change in the maxillary and pterygoid volumes. Maxillary distraction osteogenesis demonstrated linear and volumetric maxillary growth during the distraction phase without clinically significant continued growth thereafter. Overcorrection is required to take into account recurrence of midface retrusion over the long term.

  2. Dental image replacement on cone beam computed tomography with three-dimensional optical scanning of a dental cast, occlusal bite, or bite tray impression.

    Science.gov (United States)

    Kang, S-H; Lee, J-W; Lim, S-H; Kim, Y-H; Kim, M-K

    2014-10-01

    The goal of the present study was to compare the accuracy of dental image replacement on a cone beam computed tomography (CBCT) image using digital image data from three-dimensional (3D) optical scanning of a dental cast, occlusal bite, and bite tray impression. A Bracket Typodont dental model was used. CBCT of the dental model was performed and the data were converted to stereolithography (STL) format. Three experimental materials, a dental cast, occlusal bite, and bite tray impression, were optically scanned in 3D. STL files converted from the CBCT of the Typodont model and the 3D optical-scanned STL files of the study materials were image-registered. The error range of each methodology was measured and compared with a 3D optical scan of the Typodont. For the three materials, the smallest error observed was 0.099±0.114mm (mean error±standard deviation) for registering the 3D optical scan image of the dental cast onto the CBCT dental image. Although producing a dental cast can be laborious, the study results indicate that it is the preferred method. In addition, an occlusal bite is recommended when bite impression materials are used. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  3. The use of cone beam computed tomography and three dimensional printing technology in the restoration of a maxillectomy patient using a dental implant retained obturator.

    Science.gov (United States)

    Michelinakis, George

    2017-01-01

    This case report presents an alternative method for fabricating an obturator for patients that develop xerostomia and mild trismus following radiation to the Head and Neck region. Multiple initial impression stages are avoided leading to less irritation to soft tissues and less discomfort to the patient. A 69-year-old male patient was referred to our dental practice by the Maxillofacial Surgery Department of the local General Hospital. The patient had undergone a right maxillectomy for removal of a Squamous Cell Carcinoma 2 weeks prior. Four endosseous dental implants were placed in the remaining upper jaw and 2 implants were inserted into the canine region of his edentulous mandible 3 weeks after ablative surgery. Five months following completion of radiotherapy and chemotherapy, a cone beam computed tomography of the maxilla was obtained, and a three dimensional model was constructed using an appropriate resin. Using the model as the detailed primary cast, a custom acrylic special tray was fabricated for the final impression of the remaining maxilla and the maxillary defect. An implant retained maxillary obturator and an implant retained mandibular overdenture were constructed to restore patient's speech, mastication and deglutition. The method presented here can limit the impression stages needed for construction of a maxillary obturator prosthesis to a single impression procedure advocating a partial digital workflow process. This can be very beneficial to the patient suffering from postradiation side-effects such as trismus, mucositis, and xerostomia.

  4. The use of cone beam computed tomography and three dimensional printing technology in the restoration of a maxillectomy patient using a dental implant retained obturator

    Directory of Open Access Journals (Sweden)

    George Michelinakis

    2017-01-01

    Full Text Available This case report presents an alternative method for fabricating an obturator for patients that develop xerostomia and mild trismus following radiation to the Head and Neck region. Multiple initial impression stages are avoided leading to less irritation to soft tissues and less discomfort to the patient. A 69-year-old male patient was referred to our dental practice by the Maxillofacial Surgery Department of the local General Hospital. The patient had undergone a right maxillectomy for removal of a Squamous Cell Carcinoma 2 weeks prior. Four endosseous dental implants were placed in the remaining upper jaw and 2 implants were inserted into the canine region of his edentulous mandible 3 weeks after ablative surgery. Five months following completion of radiotherapy and chemotherapy, a cone beam computed tomography of the maxilla was obtained, and a three dimensional model was constructed using an appropriate resin. Using the model as the detailed primary cast, a custom acrylic special tray was fabricated for the final impression of the remaining maxilla and the maxillary defect. An implant retained maxillary obturator and an implant retained mandibular overdenture were constructed to restore patient's speech, mastication and deglutition. The method presented here can limit the impression stages needed for construction of a maxillary obturator prosthesis to a single impression procedure advocating a partial digital workflow process. This can be very beneficial to the patient suffering from postradiation side-effects such as trismus, mucositis, and xerostomia.

  5. Three-dimensional visualization of the microvasculature of bile duct ligation-induced liver fibrosis in rats by x-ray phase-contrast imaging computed tomography

    Science.gov (United States)

    Xuan, Ruijiao; Zhao, Xinyan; Hu, Doudou; Jian, Jianbo; Wang, Tailing; Hu, Chunhong

    2015-07-01

    X-ray phase-contrast imaging (PCI) can substantially enhance contrast, and is particularly useful in differentiating biological soft tissues with small density differences. Combined with computed tomography (CT), PCI-CT enables the acquisition of accurate microstructures inside biological samples. In this study, liver microvasculature was visualized without contrast agents in vitro with PCI-CT using liver fibrosis samples induced by bile duct ligation (BDL) in rats. The histological section examination confirmed the correspondence of CT images with the microvascular morphology of the samples. By means of the PCI-CT and three-dimensional (3D) visualization technique, 3D microvascular structures in samples from different stages of liver fibrosis were clearly revealed. Different types of blood vessels, including portal veins and hepatic veins, in addition to ductular proliferation and bile ducts, could be distinguished with good sensitivity, excellent specificity and excellent accuracy. The study showed that PCI-CT could assess the morphological changes in liver microvasculature that result from fibrosis and allow characterization of the anatomical and pathological features of the microvasculature. With further development of PCI-CT technique, it may become a novel noninvasive imaging technique for the auxiliary analysis of liver fibrosis.

  6. 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.

  7. Effect of the high-pitch mode in dual-source computed tomography on the accuracy of three-dimensional volumetry of solid pulmonary nodules: A phantom study

    International Nuclear Information System (INIS)

    Hwang, Sung Ho; Oh, Yu Whan; Ham, Soo Youn; Kang, Eun Young; Lee, Ki Yeol

    2015-01-01

    To evaluate the influence of high-pitch mode (HPM) in dual-source computed tomography (DSCT) on the accuracy of three-dimensional (3D) volumetry for solid pulmonary nodules. A lung phantom implanted with 45 solid pulmonary nodules (n = 15 for each of 4-mm, 6-mm, and 8-mm in diameter) was scanned twice, first in conventional pitch mode (CPM) and then in HPM using DSCT. The relative percentage volume errors (RPEs) of 3D volumetry were compared between the HPM and CPM. In addition, the intermode volume variability (IVV) of 3D volumetry was calculated. In the measurement of the 6-mm and 8-mm nodules, there was no significant difference in RPE (p > 0.05, respectively) between the CPM and HPM (IVVs of 1.2 +/- 0.9%, and 1.7 +/- 1.5%, respectively). In the measurement of the 4-mm nodules, the mean RPE in the HPM (35.1 +/- 7.4%) was significantly greater (p < 0.01) than that in the CPM (18.4 +/- 5.3%), with an IVV of 13.1 +/- 6.6%. However, the IVVs were in an acceptable range (< 25%), regardless of nodule size. The accuracy of 3D volumetry with HPM for solid pulmonary nodule is comparable to that with CPM. However, the use of HPM may adversely affect the accuracy of 3D volumetry for smaller (< 5 mm in diameter) nodule.

  8. Effect of the high-pitch mode in dual-source computed tomography on the accuracy of three-dimensional volumetry of solid pulmonary nodules: A phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sung Ho; Oh, Yu Whan; Ham, Soo Youn [Dept. of Radiology, Korea University Anam Hospital, Seoul (Korea, Republic of); Kang, Eun Young [Dept. of Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of); Lee, Ki Yeol [Dept. of Radiology, Korea University Ansan Hospital, Ansan (Korea, Republic of)

    2015-06-15

    To evaluate the influence of high-pitch mode (HPM) in dual-source computed tomography (DSCT) on the accuracy of three-dimensional (3D) volumetry for solid pulmonary nodules. A lung phantom implanted with 45 solid pulmonary nodules (n = 15 for each of 4-mm, 6-mm, and 8-mm in diameter) was scanned twice, first in conventional pitch mode (CPM) and then in HPM using DSCT. The relative percentage volume errors (RPEs) of 3D volumetry were compared between the HPM and CPM. In addition, the intermode volume variability (IVV) of 3D volumetry was calculated. In the measurement of the 6-mm and 8-mm nodules, there was no significant difference in RPE (p > 0.05, respectively) between the CPM and HPM (IVVs of 1.2 +/- 0.9%, and 1.7 +/- 1.5%, respectively). In the measurement of the 4-mm nodules, the mean RPE in the HPM (35.1 +/- 7.4%) was significantly greater (p < 0.01) than that in the CPM (18.4 +/- 5.3%), with an IVV of 13.1 +/- 6.6%. However, the IVVs were in an acceptable range (< 25%), regardless of nodule size. The accuracy of 3D volumetry with HPM for solid pulmonary nodule is comparable to that with CPM. However, the use of HPM may adversely affect the accuracy of 3D volumetry for smaller (< 5 mm in diameter) nodule.

  9. Effect of the high-pitch mode in dual-source computed tomography on the accuracy of three-dimensional volumetry of solid pulmonary nodules: a phantom study.

    Science.gov (United States)

    Hwang, Sung Ho; Oh, Yu-Whan; Ham, Soo-Youn; Kang, Eun-Young; Lee, Ki Yeol

    2015-01-01

    To evaluate the influence of high-pitch mode (HPM) in dual-source computed tomography (DSCT) on the accuracy of three-dimensional (3D) volumetry for solid pulmonary nodules. A lung phantom implanted with 45 solid pulmonary nodules (n = 15 for each of 4-mm, 6-mm, and 8-mm in diameter) was scanned twice, first in conventional pitch mode (CPM) and then in HPM using DSCT. The relative percentage volume errors (RPEs) of 3D volumetry were compared between the HPM and CPM. In addition, the intermode volume variability (IVV) of 3D volumetry was calculated. In the measurement of the 6-mm and 8-mm nodules, there was no significant difference in RPE (p > 0.05, respectively) between the CPM and HPM (IVVs of 1.2 ± 0.9%, and 1.7 ± 1.5%, respectively). In the measurement of the 4-mm nodules, the mean RPE in the HPM (35.1 ± 7.4%) was significantly greater (p volumetry with HPM for solid pulmonary nodule is comparable to that with CPM. However, the use of HPM may adversely affect the accuracy of 3D volumetry for smaller (< 5 mm in diameter) nodule.

  10. Use of cone-beam computed tomography and three-dimensional modeling for assessment of anomalous pulp canal configuration: a case report

    Directory of Open Access Journals (Sweden)

    Alper Sinanoglu

    2015-05-01

    Full Text Available Three-dimensional (3D reconstruction of cone-beam computed tomography (CBCT scans appears to be a valuable method for assessing pulp canal configuration. The aim of this report is to describe endodontic treatment of a mandibular second premolar with aberrant pulp canal morphology detected by CBCT and confirmed by 3D modeling. An accessory canal was suspected during endodontic treatment of the mandibular left second premolar in a 21 year old woman with a chief complaint of pulsating pain. Axial cross-sectional CBCT scans revealed that the pulp canal divided into mesiobuccal, lingual, and buccal canals in the middle third and ended as four separate foramina. 3D modeling confirmed the anomalous configuration of the fused root with a deep lingual groove. Endodontic treatment of the tooth was completed in two appointments. The root canals were obturated using lateral compaction of gutta-percha and root canal sealer. The tooth remained asymptomatic and did not develop periapical pathology until 12 months postoperatively. CBCT and 3D modeling enable preoperative evaluation of aberrant root canal systems and facilitate endodontic treatment.

  11. Reliability of a coordinate system based on anatomical landmarks of the maxillofacial skeleton. An evaluation method for three-dimensional images obtained by cone-beam computed tomography

    International Nuclear Information System (INIS)

    Kimura, Momoko; Nawa, Hiroyuki; Yoshida, Kazuhito; Muramatsu, Atsushi; Fuyamada, Mariko; Goto, Shigemi; Ariji, Eiichiro; Tokumori, Kenji; Katsumata, Akitoshi

    2009-01-01

    We propose a method for evaluating the reliability of a coordinate system based on maxillofacial skeletal landmarks and use it to assess two coordinate systems. Scatter plots and 95% confidence ellipses of an objective landmark were defined as an index for demonstrating the stability of the coordinate system. A head phantom was positioned horizontally in reference to the Frankfurt horizontal and occlusal planes and subsequently scanned once in each position using cone-beam computed tomography. On the three-dimensional images created with a volume-rendering procedure, six dentists twice set two different coordinate systems: coordinate system 1 was defined by the nasion, sella, and basion, and coordinate system 2 was based on the left orbitale, bilateral porions, and basion. The menton was assigned as an objective landmark. The scatter plot and 95% ellipse of the menton indicated the high-level reliability of coordinate system 2. The patterns with the two coordinate systems were similar between data obtained in different head positions. The method presented here may be effective for evaluating the reliability (reproducibility) of coordinate systems based on skeletal landmarks. (author)

  12. Extracting Metrics for Three-dimensional Root Systems: Volume and Surface Analysis from In-soil X-ray Computed Tomography Data.

    Science.gov (United States)

    Suresh, Niraj; Stephens, Sean A; Adams, Lexor; Beck, Anthon N; McKinney, Adriana L; Varga, Tamas

    2016-04-26

    Plant roots play a critical role in plant-soil-microbe interactions that occur in the rhizosphere, as well as processes with important implications to climate change and crop management. Quantitative size information on roots in their native environment is invaluable for studying root growth and environmental processes involving plants. X-ray computed tomography (XCT) has been demonstrated to be an effective tool for in situ root scanning and analysis. We aimed to develop a costless and efficient tool that approximates the surface and volume of the root regardless of its shape from three-dimensional (3D) tomography data. The root structure of a Prairie dropseed (Sporobolus heterolepis) specimen was imaged using XCT. The root was reconstructed, and the primary root structure was extracted from the data using a combination of licensed and open-source software. An isosurface polygonal mesh was then created for ease of analysis. We have developed the standalone application imeshJ, generated in MATLAB(1), to calculate root volume and surface area from the mesh. The outputs of imeshJ are surface area (in mm(2)) and the volume (in mm(3)). The process, utilizing a unique combination of tools from imaging to quantitative root analysis, is described. A combination of XCT and open-source software proved to be a powerful combination to noninvasively image plant root samples, segment root data, and extract quantitative information from the 3D data. This methodology of processing 3D data should be applicable to other material/sample systems where there is connectivity between components of similar X-ray attenuation and difficulties arise with segmentation.

  13. Gated 99mTc-MIBI single-photon emission computed tomography for the evaluation of left ventricular ejection fraction. Comparison with three-dimensional echocardiography

    International Nuclear Information System (INIS)

    Lipiec, P.; Wejner-Mik, P.; Krzeminska-Pakula, M.; Kapusta, A.; Kasprzak, J.D.; Kusmierek, J.; Plachcinska, A.; Szuminski, R.

    2008-01-01

    Parameters of left ventricular systolic function directly influence the management of patients with suspected coronary artery disease (CAD). Quantitative gated single-photon emission computed tomography (QGS; Cedars-Sinai Medical Center, Los Angeles, CA, USA) allows the computation of left ventricular ejection fraction (LVEF) from myocardial perfusion imaging studies which are frequently performed on patients with suspected CAD. Three-dimensional (3D) echocardiography is considered to be the echocardiographic ''gold standard'' for the quantification of LVEF. We sought to compare QGS with 3D echocardiography in the evaluation of EF in patients with suspected CAD. Ninety-one consecutive patients with suspected CAD, scheduled for coronary angiography, underwent rest electrocardiographic-gated technetium-99m methoxyisobutylisonitrile SPECT (G-SPECT) with measurement of LVEF by QGS and transthoracic 3D echocardiography with off-line measurement of LVEF (Tomtec 4D LV Analysis 1.1). The diagnosis of CAD was based on coronary angiography, performed on every patient. Nine patients were excluded from the analysis owing to unsuitability for 3D echocardiography (8 patients) or G-SPECT (1 patient). In the remaining group of 82 patients, 71 (87%) had significant CAD, 34 (42%) had a history of myocardial infarction, and 50 (61%) had perfusion defects at rest G-SPECT images. The mean LVEF measured by QGS and 3D echocardiography was 53±13% and 53±10%, respectively. The mean difference in LVEF between 3D echocardiography and QGS was 0.1±6.0% (P=0.87), and the correlation between the values obtained by both methods was high (r=0.88, P< 0.001). The largest discrepancies were observed in patients with small ventricular volumes. In patients undergoing diagnostic work-up for CAD, the measurement of LVEF by QGS algorithm provides high correlation and satisfactory agreement with the results of reference ultrasound method- 3D echocardiography. (author)

  14. Computed Tomography Based Three-dimensional Measurements of Spine Shortening Distance After Posterior Three-column Osteotomies for the Treatment of Severe and Stiff Scoliosis.

    Science.gov (United States)

    Li, Xue-Shi; Huang, Zi-Fang; Deng, Yao-Long; Fan, Heng-Wei; Sui, Wen-Yuan; Wang, Chong-Wen; Yang, Jun-Lin

    2017-07-15

    Retrospective study. This study is to measure and analyze the changes of three-dimensional (3D) distances of spinal column and spinal canal at the three-column osteotomy sites and address their clinical and neurologic significance. Three-column osteotomies were developed to treat severe and stiff spine deformities with insufficient understanding on the safe limit of spine shortening and the relationship between the shortening distance of the spinal column and that of the spinal canal. Records of 52 continuous patients with severe and stiff scoliosis treated with three-column spine osteotomies at our institution from July 2013 to June 2015 were reviewed. The preoperative spinal cord function classification were type A in 31 cases, type B in 10 cases, and type C in 11 cases. The types of osteotomies carried out were extended pedicle subtraction osteotomy in nine patients and posterior vertebral column resection in 43 patients. Multimodality neuromonitoring strategies were adopted intraoperatively. 3D pre- and postoperative spine models were reconstructed from the computed tomography (CT) scans. The distances of convex and concave spinal column and the spinal canal shortening were measured and analyzed. The spinal column shortening distance (SCSD) measured on the 3D models (27.8 mm) were statistically shorter than those measured intraoperatively (32.8 mm) (P column strut graft than in those with bone-on-bone fusion (P column cannot represent that of the central spinal canal in patients with severe scoliosis. The spinal column shortening procedure in appropriately selected patient groups with bone-on-bone fusion is a viable option with the CCSD being significantly shorter than the convex SCSD. 4.

  15. Accuracy of Cup Positioning With the Computed Tomography-Based Two-dimensional to Three-Dimensional Matched Navigation System: A Prospective, Randomized Controlled Study.

    Science.gov (United States)

    Yamada, Kazuki; Endo, Hirosuke; Tetsunaga, Tomonori; Miyake, Takamasa; Sanki, Tomoaki; Ozaki, Toshifumi

    2018-01-01

    The accuracy of various navigation systems used for total hip arthroplasty has been described, but no publications reported the accuracy of cup orientation in computed tomography (CT)-based 2D-3D (two-dimensional to three-dimensional) matched navigation. In a prospective, randomized controlled study, 80 hips including 44 with developmental dysplasia of the hips were divided into a CT-based 2D-3D matched navigation group (2D-3D group) and a paired-point matched navigation group (PPM group). The accuracy of cup orientation (absolute difference between the intraoperative record and the postoperative measurement) was compared between groups. Additionally, multiple logistic regression analysis was performed to evaluate patient factors affecting the accuracy of cup orientation in each navigation. The accuracy of cup inclination was 2.5° ± 2.2° in the 2D-3D group and 4.6° ± 3.3° in the PPM group (P = .0016). The accuracy of cup anteversion was 2.3° ± 1.7° in the 2D-3D group and 4.4° ± 3.3° in the PPM group (P = .0009). In the PPM group, the presence of roof osteophytes decreased the accuracy of cup inclination (odds ratio 8.27, P = .0140) and the absolute value of pelvic tilt had a negative influence on the accuracy of cup anteversion (odds ratio 1.27, P = .0222). In the 2D-3D group, patient factors had no effect on the accuracy of cup orientation. The accuracy of cup positioning in CT-based 2D-3D matched navigation was better than in paired-point matched navigation, and was not affected by patient factors. It is a useful system for even severely deformed pelvises such as developmental dysplasia of the hips. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Three-dimensional quantification of orthodontic root resorption with time-lapsed imaging of micro-computed tomography in a rodent model.

    Science.gov (United States)

    Yang, Chongshi; Zhang, Yuanyuan; Zhang, Yan; Fan, Yubo; Deng, Feng

    2015-01-01

    Despite various X-ray approaches have been widely used to monitor root resorption after orthodontic treatment, a non-invasive and accurate method is highly desirable for long-term follow up. The aim of this study was to build a non-invasive method to quantify longitudinal orthodontic root resorption with time-lapsed images of micro-computed tomography (micro-CT) in a rodent model. Twenty male Sprague Dawley (SD) rats (aged 6-8 weeks, weighing 180-220 g) were used in this study. A 25 g orthodontic force generated by nickel-titanium coil spring was applied to the right maxillary first molar for each rat, while contralateral first molar was severed as a control. Micro-CT scan was performed at day 0 (before orthodontic load) and days 3, 7, 14, and 28 after orthodontic load. Resorption of mesial root of maxillary first molars at bilateral sides was calculated from micro-CT images with registration algorithm via reconstruction, superimposition and partition operations. Obvious resorption of mesial root of maxillary first molar can be detected at day 14 and day 28 at orthodontic side. Most of the resorption occurred in the apical region at distal side and cervical region at mesiolingual side. Desirable development of molar root of rats was identified from day 0 to day 28 at control side. The development of root concentrated on apical region. This non-invasive 3D quantification method with registration algorithm can be used in longitudinal study of root resorption. Obvious root resorption in rat molar can be observed three-dimensionally at day 14 and day 28 after orthodontic load. This indicates that registration algorithm combined with time-lapsed images provides clinic potential application in detection and quantification of root contour.

  17. High and intermediate risk prostate cancer treated with three-dimensional computed tomography-guided brachytherapy: 2-8-year follow-up

    International Nuclear Information System (INIS)

    Koutrouvelis, Panos G.; Gillenwater, Jay; Lailas, Niko; Hendricks, Fred; Katz, Stuart; Sehn, James; Gil-Montero, Guillermo; Khawand, Nabil

    2003-01-01

    Purpose: To report post-brachytherapy results in high and intermediate risk patients of prostatic adenocarcinoma. Methods and materials: From June 1994 to June 2000, 356 consecutive high and intermediate risk patients were treated with three-dimensional computed tomography-guided stereotactic pararectal brachytherapy. The age was 42-90 years (median, 68 years), the initial prostate volume was 14-180 cm 3 (median, 59 cm 3 ), and initial PSA was 1.7-143 ng/ml (median, 10.5 ng/ml). Three hundred forty-eight patients were available for follow-up for 2 - 8 years (median, 4.5 years). Two hundred eighty patients had one or more high risk factors (PSA >20 ng/ml, Gleason>7, Stage T2b, T3a, or T3b). Sixty-eight patients had only one intermediate risk factor (PSA 10-20 ng/ml or Gleason=7). Patients with both intermediate risks were considered high risk. The high-risk group was further stratified into subgroups with similar risk profile. A dose of 144 Gy with 125 I or 120 Gy with 103 Pd was achieved in 90-100% of the target. Thirty (30) patients (9%) had prior transurethral resection and 229 (64%) were treated with 3 months neoadjuvant androgen ablation. Results: Biochemical disease-free survival was 92% of 280 high risk patients and 96% of 68 intermediate risk patients. Seven patients (2%) required catheterization during the first year for urinary retention, nine patients (3%) required TUR 1-3 years post-implant, three patients (1%) developed grade 1 or 2 incontinence after a second TUR, and four patients (1%) developed grade 3 rectal complications. Conclusion: This method produces a high level of biochemical control 2-8 years (median 4.5 years). Morbidity is acceptable regardless of risk profile or initial prostate volume

  18. Three-dimensional echocardiography in various types of heart disease: a comparison study of magnetic resonance imaging and 64-slice computed tomography in a real-world population.

    Science.gov (United States)

    Squeri, Angelo; Censi, Stefano; Reverberi, Claudio; Gaibazzi, Nicola; Baldelli, Marco; Binno, Simone Maurizio; Properzi, Enrico; Bosi, Stefano

    2017-03-01

    Accurate quantification of left ventricular (LV) volumes [end-diastolic volume (EDV) and end-systolic volume (ESV)] and ejection fraction (EF) is of critical importance. The development of real-time three-dimensional echocardiography (RT3DE) has shown better correlation than two-dimensional (2D) echocardiography with magnetic resonance imaging (MRI) measurements. The aim of our study was to assess the accuracy of RT3DE and 64-slice computed tomography (CT) in the evaluation of LV volumes and function using MRI as the reference standard in a real-world population with various types of heart disease with different chamber geometry. The study population consisted of 66 patients referred for cardiac MRI for various pathologies. All patients underwent cardiac MRI, and RT3DE and 64 slices CT were then performed on a subsequent day. The study population was then divided into 5 clinical groups depending on the underlying heart disease. RT3DE volumes correlated well with MRI values (R 2 values: 0.90 for EDV and 0.94 for ESV). RT3DE measurements of EF correlated well with MRI values (R 2  = 0.86). RT3DE measurements resulted in slightly underestimated values of both EDV and ESV, as reflected by biases of -9.18 and -4.50 mL, respectively. Comparison of RT3DE and MRI in various types of cardiomyopathies showed no statistical difference between different LV geometrical patterns. These results confirm that RT3DE has good accuracy in everyday clinical practice and can be of clinical utility in all types of cardiomyopathy independently of LV geometric pattern, LV diameter or wall thickness, taking into account a slight underestimation of LV volumes and EF compared to MRI.

  19. Development and Clinical Evaluation of a Three-Dimensional Cone-Beam Computed Tomography Estimation Method Using a Deformation Field Map

    International Nuclear Information System (INIS)

    Ren, Lei; Chetty, Indrin J.; Zhang Junan; Jin Jianyue; Wu, Q. Jackie; Yan Hui; Brizel, David M.; Lee, W. Robert; Movsas, Benjamin; Yin Fangfang

    2012-01-01

    Purpose: To develop a three-dimensional (3D) cone-beam computed tomography (CBCT) estimation method using a deformation field map, and to evaluate and optimize the efficiency and accuracy of the method for use in the clinical setting. Methods and Materials: We propose a method to estimate patient CBCT images using prior information and a deformation model. Patients’ previous CBCT data are used as the prior information, and the new CBCT volume to be estimated is considered as a deformation of the prior image volume. The deformation field map is solved by minimizing deformation energy and maintaining new projection data fidelity using a nonlinear conjugate gradient method. This method was implemented in 3D form using hardware acceleration and multi-resolution scheme, and it was evaluated for different scan angles, projection numbers, and scan directions using liver, lung, and prostate cancer patient data. The accuracy of the estimation was evaluated by comparing the organ volume difference and the similarity between estimated CBCT and the CBCT reconstructed from fully sampled projections. Results: Results showed that scan direction and number of projections do not have significant effects on the CBCT estimation accuracy. The total scan angle is the dominant factor affecting the accuracy of the CBCT estimation algorithm. Larger scan angles yield better estimation accuracy than smaller scan angles. Lung cancer patient data showed that the estimation error of the 3D lung tumor volume was reduced from 13.3% to 4.3% when the scan angle was increased from 60° to 360° using 57 projections. Conclusions: The proposed estimation method is applicable for 3D DTS, 3D CBCT, four-dimensional CBCT, and four-dimensional DTS image estimation. This method has the potential for significantly reducing the imaging dose and improving the image quality by removing the organ distortion artifacts and streak artifacts shown in images reconstructed by the conventional Feldkamp

  20. Three-dimensional multifunctional optical coherence tomography for skin imaging

    Science.gov (United States)

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

    2016-02-01

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

  1. Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields

    DEFF Research Database (Denmark)

    Sales, Morten; Strobl, Markus; Shinohara, Takenao

    2018-01-01

    Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non-destructively wi......Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non...... and reconstructed, thereby providing the proof-of-principle of a technique able to reveal hitherto unobtainable information on the magnetic fields in the bulk of materials and devices, due to a high degree of penetration into many materials, including metals, and the sensitivity of neutron polarisation to magnetic...... fields. The technique puts the potential of the ToF time structure of pulsed neutron sources to full use in order to optimise the recorded information quality and reduce measurement time....

  2. Change of Femoral Anteversion Angle in Children With Intoeing Gait Measured by Three-Dimensional Computed Tomography Reconstruction: One-Year Follow-Up Study.

    Science.gov (United States)

    Kong, Minsik; Jo, Hongsik; Lee, Chang Han; Chun, Se-Woong; Yoon, Chulho; Shin, Heesuk

    2018-02-01

    To evaluate femoral anteversion angle (FAA) change in children with intoeing gait depending on age, gender, and initial FAA using three-dimensional computed tomography (3D-CT). The 3D-CT data acquired between 2006 and 2016 were retrospectively reviewed. Children 4 to 10 years of age with symptomatic intoeing gait with follow-up interval of at least 1 year without active treatment were enrolled. Subjects were divided into three groups based on age: group 1 (≥4 and FAAs were measured using 3D-CT. Mean changes in FAAs were calculated and compared. A total of 200 lower limbs of 100 children (48 males and 52 females, mean age of 6.1±1.6 years) were included. The mean follow-up period was 18.0±5.4 months. Average initial and follow-up FAA in children with intoeing gait was 31.1°±7.8° and 28.9°±8.2°, respectively. The initial FAA of group 1 was largest (33.5°±7.7°). Follow-up FAA of group 1 was significantly reduced to 28.7°±9.2° (p=0.000). FAA changes in groups 1, 2, and 3 were -6.5°±5.8°, -6.4°±5.1°, and -5.3°±4.0°, respectively. These changes of FAA were not significantly (p=0.355) different among the three age groups. However, FAA changes were higher (p=0.012) in females than those in males. In addition, FAA changes showed difference depending on initial FAA. When initial FAA was smaller than 30°, mean FAA change was -5.6°±4.9°. When initial FAA was more than 30°, mean FAA change was -6.8°±5.4° (p=0.019). FAA initial in children with intoeing gait was the greatest in age group 1 (4-6 years). This group also showed significant FAA decrease at follow-up. FAA changes were greater when the child was a female, younger, and had greater initial FAA.

  3. Accuracy of Ultrasound-Based (BAT) Prostate-Repositioning: A Three-Dimensional On-Line Fiducial-Based Assessment With Cone-Beam Computed Tomography

    International Nuclear Information System (INIS)

    Boda-Heggemann, Judit; Koehler, Frederick Marc; Kuepper, Beate; Wolff, Dirk; Wertz, Hansjoerg; Mai, Sabine; Hesser, Juergen; Lohr, Frank; Wenz, Frederik

    2008-01-01

    Purpose: To assess the accuracy of ultrasound-based repositioning (BAT) before prostate radiation with fiducial-based three-dimensional matching with cone-beam computed tomography (CBCT). Patients and Methods: Fifty-four positionings in 8 patients with 125 I seeds/intraprostatic calcifications as fiducials were evaluated. Patients were initially positioned according to skin marks and after this according to bony structures based on CBCT. Prostate position correction was then performed with BAT. Residual error after repositioning based on skin marks, bony anatomy, and BAT was estimated by a second CBCT based on user-independent automatic fiducial registration. Results: Overall mean value (MV ± SD) residual error after BAT based on fiducial registration by CBCT was 0.7 ± 1.7 mm in x (group systematic error [M] = 0.5 mm; SD of systematic error [Σ] = 0.8 mm; SD of random error [σ] = 1.4 mm), 0.9 ± 3.3 mm in y (M = 0.5 mm, Σ = 2.2 mm, σ = 2.8 mm), and -1.7 ± 3.4 mm in z (M = -1.7 mm, Σ = 2.3 mm, σ = 3.0 mm) directions, whereas residual error relative to positioning based on skin marks was 2.1 ± 4.6 mm in x (M = 2.6 mm, Σ = 3.3 mm, σ = 3.9 mm), -4.8 ± 8.5 mm in y (M = -4.4 mm, Σ = 3.7 mm, σ = 6.7 mm), and -5.2 ± 3.6 mm in z (M = -4.8 mm, Σ = 1.7 mm, σ = 3.5mm) directions and relative to positioning based on bony anatomy was 0 ± 1.8 mm in x (M = 0.2 mm, Σ = 0.9 mm, σ = 1.1 mm), -3.5 ± 6.8 mm in y (M = -3.0 mm, Σ = 1.8 mm, σ = 3.7 mm), and -1.9 ± 5.2 mm in z (M = -2.0 mm, Σ = 1.3 mm, σ = 4.0 mm) directions. Conclusions: BAT improved the daily repositioning accuracy over skin marks or even bony anatomy. The results obtained with BAT are within the precision of extracranial stereotactic procedures and represent values that can be achieved with several users with different education levels. If sonographic visibility is insufficient, CBCT or kV/MV portal imaging with implanted fiducials are recommended

  4. Imaging the Aqueous Humor Outflow Pathway in Human Eyes by Three-dimensional Micro-computed Tomography (3D micro-CT)

    Energy Technology Data Exchange (ETDEWEB)

    C Hann; M Bentley; A Vercnocke; E Ritman; M Fautsch

    2011-12-31

    The site of outflow resistance leading to elevated intraocular pressure in primary open-angle glaucoma is believed to be located in the region of Schlemm's canal inner wall endothelium, its basement membrane and the adjacent juxtacanalicular tissue. Evidence also suggests collector channels and intrascleral vessels may have a role in intraocular pressure in both normal and glaucoma eyes. Traditional imaging modalities limit the ability to view both proximal and distal portions of the trabecular outflow pathway as a single unit. In this study, we examined the effectiveness of three-dimensional micro-computed tomography (3D micro-CT) as a potential method to view the trabecular outflow pathway. Two normal human eyes were used: one immersion fixed in 4% paraformaldehyde and one with anterior chamber perfusion at 10 mmHg followed by perfusion fixation in 4% paraformaldehyde/2% glutaraldehyde. Both eyes were postfixed in 1% osmium tetroxide and scanned with 3D micro-CT at 2 {mu}m or 5 {mu}m voxel resolution. In the immersion fixed eye, 24 collector channels were identified with an average orifice size of 27.5 {+-} 5 {mu}m. In comparison, the perfusion fixed eye had 29 collector channels with a mean orifice size of 40.5 {+-} 13 {mu}m. Collector channels were not evenly dispersed around the circumference of the eye. There was no significant difference in the length of Schlemm's canal in the immersed versus the perfused eye (33.2 versus 35.1 mm). Structures, locations and size measurements identified by 3D micro-CT were confirmed by correlative light microscopy. These findings confirm 3D micro-CT can be used effectively for the non-invasive examination of the trabecular meshwork, Schlemm's canal, collector channels and intrascleral vasculature that comprise the distal outflow pathway. This imaging modality will be useful for non-invasive study of the role of the trabecular outflow pathway as a whole unit.

  5. Comparison of two three-dimensional cephalometric analysis computer software.

    Science.gov (United States)

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-10-01

    Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Twenty cone beam computed tomography images were obtained using i-CAT(®) imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (University of Illinois at Chicago, Chicago, IL, USA) software. Before and after orthodontic treatments data were analyzed using t-test. Reliability test using interclass correlation coefficient was stronger for InVivoDental5.0 (0.83-0.98) compared with 3DCeph™ (0.51-0.90). Paired t-test comparison of the two softwares shows no statistical significant difference in the measurements made in the two softwares. InVivoDental5.0 measurements are more reproducible and user friendly when compared to 3DCeph™. No statistical difference between the two softwares in linear or angular measurements. 3DCeph™ is more time-consuming in performing three-dimensional analysis compared with InVivoDental5.0.

  6. The impact of different cone beam computed tomography and multi-slice computed tomography scan parameters on virtual three-dimensional model accuracy using a highly precise ex vivo evaluation method.

    Science.gov (United States)

    Matta, Ragai-Edward; von Wilmowsky, Cornelius; Neuhuber, Winfried; Lell, Michael; Neukam, Friedrich W; Adler, Werner; Wichmann, Manfred; Bergauer, Bastian

    2016-05-01

    Multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) are indispensable imaging techniques in advanced medicine. The possibility of creating virtual and corporal three-dimensional (3D) models enables detailed planning in craniofacial and oral surgery. The objective of this study was to evaluate the impact of different scan protocols for CBCT and MSCT on virtual 3D model accuracy using a software-based evaluation method that excludes human measurement errors. MSCT and CBCT scans with different manufacturers' predefined scan protocols were obtained from a human lower jaw and were superimposed with a master model generated by an optical scan of an industrial noncontact scanner. To determine the accuracy, the mean and standard deviations were calculated, and t-tests were used for comparisons between the different settings. Averaged over 10 repeated X-ray scans per method and 19 measurement points per scan (n = 190), it was found that the MSCT scan protocol 140 kV delivered the most accurate virtual 3D model, with a mean deviation of 0.106 mm compared to the master model. Only the CBCT scans with 0.2-voxel resolution delivered a similar accurate 3D model (mean deviation 0.119 mm). Within the limitations of this study, it was demonstrated that the accuracy of a 3D model of the lower jaw depends on the protocol used for MSCT and CBCT scans. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  7. Influence of heart rhythm, breathing and arm position during computed tomography scanning on the registration accuracy of electro anatomical map (EAM) images, left atrium three-dimensional computed tomography angiography images, and fluoroscopy time during ablation to treat atrial fibrillation

    International Nuclear Information System (INIS)

    Chono, Taiki; Shimoshige, Shinya; Yoshikawa, Kenta; Mizonobe, Kazuhusa; Ogura, Keishi

    2013-01-01

    In CARTOMERGE for treatment of atrial fibrillation (AF) by ablation, by integrating electro anatomical map (EAM) and left atrium three-dimensional computed tomography angiography (3D-CTA) images, identification of the ablation points is simplified and the procedure can be made carried out more rapidly. However, the influence that heart rhythm, breathing and arm position during CT scanning have on registration accuracy and fluoroscopy time is not clear. To clarify the influence on registration accuracy and fluoroscopy time of heart rhythm, breathing and arm position during CT scanning. The patients were CT-scanned during both sinus rhythm (SR) and AF in each study subject. We evaluated the registration accuracy of images reconstructed between the cardiac cycle and assessed the registration accuracy and fluoroscopy time of images obtained during inspiratory breath-hold, expiratory breath-hold and up and down position of the arm. Although the registration accuracy of the EAM image and left atrium 3D-CTA image showed a significant difference during SR, no significant difference was seen during AF. Expiratory breath-hold and down position of the arm resulted in the highest registration accuracy and the shortest fluoroscopy time. However, arm position had no significant effect on registration accuracy. Heart rhythm and breathing during CT scanning have a significant effect on the registration accuracy of EAM images, left atrium 3D-CTA images, and fluoroscopy time. (author)

  8. Electron tomography, three-dimensional Fourier analysis and colour prediction of a three-dimensional amorphous biophotonic nanostructure

    Science.gov (United States)

    Shawkey, Matthew D.; Saranathan, Vinodkumar; Pálsdóttir, Hildur; Crum, John; Ellisman, Mark H.; Auer, Manfred; Prum, Richard O.

    2009-01-01

    Organismal colour can be created by selective absorption of light by pigments or light scattering by photonic nanostructures. Photonic nanostructures may vary in refractive index over one, two or three dimensions and may be periodic over large spatial scales or amorphous with short-range order. Theoretical optical analysis of three-dimensional amorphous nanostructures has been challenging because these structures are difficult to describe accurately from conventional two-dimensional electron microscopy alone. Intermediate voltage electron microscopy (IVEM) with tomographic reconstruction adds three-dimensional data by using a high-power electron beam to penetrate and image sections of material sufficiently thick to contain a significant portion of the structure. Here, we use IVEM tomography to characterize a non-iridescent, three-dimensional biophotonic nanostructure: the spongy medullary layer from eastern bluebird Sialia sialis feather barbs. Tomography and three-dimensional Fourier analysis reveal that it is an amorphous, interconnected bicontinuous matrix that is appropriately ordered at local spatial scales in all three dimensions to coherently scatter light. The predicted reflectance spectra from the three-dimensional Fourier analysis are more precise than those predicted by previous two-dimensional Fourier analysis of transmission electron microscopy sections. These results highlight the usefulness, and obstacles, of tomography in the description and analysis of three-dimensional photonic structures. PMID:19158016

  9. Three-Dimensional Computational Fluid Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Haworth, D.C.; O' Rourke, P.J.; Ranganathan, R.

    1998-09-01

    Computational fluid dynamics (CFD) is one discipline falling under the broad heading of computer-aided engineering (CAE). CAE, together with computer-aided design (CAD) and computer-aided manufacturing (CAM), comprise a mathematical-based approach to engineering product and process design, analysis and fabrication. In this overview of CFD for the design engineer, our purposes are three-fold: (1) to define the scope of CFD and motivate its utility for engineering, (2) to provide a basic technical foundation for CFD, and (3) to convey how CFD is incorporated into engineering product and process design.

  10. Three dimensional endo-cardiovascular volume-rendered cine computed tomography of isolated left ventricular apical hypoplasia; A case report and literature review

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sun Hwa; Kim, Yang Min; Lee, Hyun Jong [Sejong General Hospital, Bucheon (Korea, Republic of)

    2016-02-15

    We report multidetector computed tomography (MDCT) and cardiac magnetic resonance (CMR) findings of a 34-year-old female with isolated left ventricular apical hypoplasia. The MDCT and CMR scans displayed a spherical left ventricle (LV) with extensive fatty infiltration within the myocardium at the apex, interventricular septum and inferior wall, anteroapical origin of the papillary muscle, right ventricle wrapping around the deficient LV apex, and impaired systolic function. MDCT visualized morphologic and also functional findings of this unique cardiomyopathy.

  11. Prospective study comparing three-dimensional computed tomography and magnetic resonance imaging for evaluating the renal vascular anatomy in potential living renal donors.

    Science.gov (United States)

    Bhatti, Aftab A; Chugtai, Aamir; Haslam, Philip; Talbot, David; Rix, David A; Soomro, Naeem A

    2005-11-01

    To prospectively compare the accuracy of multislice spiral computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) in evaluating the renal vascular anatomy in potential living renal donors. Thirty-one donors underwent multislice spiral CTA and gadolinium-enhanced MRA. In addition to axial images, multiplanar reconstruction and maximum intensity projections were used to display the renal vascular anatomy. Twenty-four donors had a left laparoscopic donor nephrectomy (LDN), whereas seven had right open donor nephrectomy (ODN); LDN was only considered if the renal vascular anatomy was favourable on the left. CTA and MRA images were analysed by two radiologists independently. The radiological and surgical findings were correlated after the surgery. CTA showed 33 arteries and 32 veins (100% sensitivity) whereas MRA showed 32 arteries and 31 veins (97% sensitivity). CTA detected all five accessory renal arteries whereas MRA only detected one. CTA also identified all three accessory renal veins whereas MRA identified two. CTA had a sensitivity of 97% and 47% for left lumbar and left gonadal veins, whereas MRA had a sensitivity of 74% and 46%, respectively. Multislice spiral CTA with three-dimensional reconstruction was more accurate than MRA for both renal arterial and venous anatomy.

  12. Three dimensional rock microstructures: insights from FIB-SEM tomography

    Science.gov (United States)

    Drury, Martyn; Pennock, Gill; de Winter, Matthijs

    2016-04-01

    Most studies of rock microstructures investigate two-dimensional sections or thin slices of three dimensional grain structures. With advances of X-ray and electron tomography methods the 3-D microstructure can be(relatively) routinely investigated on scales from a few microns to cm. 3D studies are needed to investigate the connectivity of microstructures and to test the assumptions we use to calculate 3D properties from 2D sections. We have used FIB-SEM tomography to study the topology of melts in synthetic olivine rocks, 3D crystal growth microstructures, pore networks and subgrain structures. The technique uses a focused ion beam to make serial sections with a spacing of tens to hundreds of nanometers. Each section is then imaged or mapped using the electron beam. The 3D geometry of grains and subgrains can be investigated using orientation contrast or EBSD mapping. FIB-SEM tomography of rocks and minerals can be limited by charging of the uncoated surfaces exposed by the ion beam. The newest generation of FIB-SEMs have much improved low voltage imaging capability allowing high resolution charge free imaging. Low kV FIB-SEM tomography is now widely used to study the connectivity of pore networks. In-situ fluids can also be studied using cryo-FIB-SEM on frozen samples, although special freezing techniques are needed to avoid artifacts produced by ice crystallization. FIB-SEM tomography is complementary, in terms of spatial resolution and sampled volume, to TEM tomography and X-ray tomography, and the combination of these methods can cover a wide range of scales. Our studies on melt topology in synthetic olivine rocks with a high melt content show that many grain boundaries are wetted by nanometre scale melt layers that are too thin to resolve by X-ray tomography. A variety of melt layer geometries occur consistent with several mechanisms of melt layer formation. The nature of melt geometries along triple line junctions and quadruple points can be resolved

  13. Three-dimensional assessment of crestal bone levels at titanium implants with different abutment microstructures and insertion depths using micro-computed tomography.

    Science.gov (United States)

    Becker, Kathrin; Klitzsch, Inka; Stauber, Martin; Schwarz, Frank

    2017-06-01

    To (i) assess the impact of insertion depth and abutment microstructure on the three-dimensional crestal bone-level changes at endosseous titanium implant using μCT and computerized image processing and (ii) to correlate the findings with previously reported histology. Titanium implants (conical abutment connection) were inserted in each hemimandible of n = 6 foxhounds with the implant shoulder (IS) located either in epicrestal (0 mm), supracrestal (+1 mm) or subcrestal (-1 mm) positions and randomly (split-mouth design) connected with machined or partially micro-grooved healing abutments. At 20 weeks, the tissue biopsies were processed for μCT and histological (HI) analyses. The volumetric dehiscence profile around the implants was computed as distance between the implant shoulder (IS) and the most coronal bone-to-implant contact (CBI) using MATLAB. The respective buccal and oral values were averaged, and agreement with the respective IS-CBI scores from HI was assessed using Bland-Altman plots. A median net bone gain was observed for supracrestal insertion depths at both abutment types, but lower bounds of the 75% quartile experienced net bone losses. Epicrestal and subcrestal insertion depths were linked to slight bone losses, and the buccal and oral dehiscences were smaller compared to supracrestal positioning. Bland-Altman plots yielded a moderate agreement of IS-CBI values measured with μCT and HI. The novel image processing method allowed reliable evaluations and pointed to a direct impact of insertion depths on crestal bone-level changes. Additionally, it demonstrated that HI morphometry crucially depends on the chosen cutting position. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Three-Dimensional Cone Beam Computed Tomography Volumetric Outcomes of rhBMP-2/Demineralized Bone Matrix versus Iliac Crest Bone Graft for Alveolar Cleft Reconstruction.

    Science.gov (United States)

    Liang, Fan; Yen, Stephen L-K; Imahiyerobo, Thomas; Sanborn, Luke; Yen, Leia; Yen, Daniel; Nazarian, Sheila; Jedrzejewski, Breanna; Urata, Mark; Hammoudeh, Jeffrey

    2017-10-01

    Recent studies indicate that recombinant human bone morphogenetic protein-2 (rhBMP-2) in a demineralized bone matrix scaffold is a comparable alternative to iliac bone autograft in the setting of secondary alveolar cleft repair. Postreconstruction occlusal radiographs demonstrate improved bone stock when rhBMP-2/demineralized bone matrix (DBM) scaffold is used but lack the capacity to evaluate bone growth in three dimensions. This study uses cone beam computed tomography to provide the first clinical evaluation of volumetric and density comparisons between these two treatment modalities. A prospective study was conducted with 31 patients and 36 repairs of the alveolar cleft over a 2-year period. Twenty-one repairs used rhBMP-2/DBM scaffold and 14 repairs used iliac bone grafting. Postoperatively, occlusal radiographs were obtained at 3 months to evaluate bone fill; cone beam computed tomographic images were obtained at 6 to 9 months to compare volumetric and density data. At 3 months, postoperative occlusal radiographs demonstrated that 67 percent of patients receiving rhBMP-2/DBM scaffold had complete bone fill of the alveolus, versus 56 percent of patients in the autologous group. In contrast, cone beam computed tomographic data showed 31.6 percent (95 percent CI, 24.2 to 38.5 percent) fill in the rhBMP-2 group compared with 32.5 percent (95 percent CI, 22.1 to 42.9 percent) in the autologous population. Density analysis demonstrated identical average values between the groups (1.38 g/cc). These data demonstrate comparable bone regrowth and density values following secondary alveolar cleft repair using rhBMP-2/DBM scaffold versus autologous iliac bone graft. Cone beam computed tomography provides a more nuanced understanding of true bone regeneration within the alveolar cleft that may contribute to the information provided by occlusal radiographs alone. Therapeutic, II.

  15. Three-dimensional analysis of the pulp cavity on surface models of molar teeth, using X-ray micro-computed tomography

    DEFF Research Database (Denmark)

    Markvart, Merete; Bjørndal, Lars; Darvann, Tron Andre

    2012-01-01

    . In summary, three-dimensional surface models were made with a high precision; an increased accumulation of mineral deposits was noted in molars with small pulp chambers and combined with the consistent pattern of intra-radicular connections, the potential endodontic treatment complexity is underlined...

  16. Management of a Two-rooted Maxillary Central Incisor Using Cone-beam Computed Tomography: Importance of Three-dimensional Imaging

    Directory of Open Access Journals (Sweden)

    Saurabh Kumar Gupta

    2015-09-01

    Full Text Available We report a rare case of a two-rooted maxillary central incisor, stressing the importance of three-dimensional imaging in treatment planning and conservative approach of management. Endodontic treatment of this central incisor was carried out with a successful outcome.

  17. A comparative study of three-dimensional reconstructive images of temporomandibular joint using computed tomogram

    International Nuclear Information System (INIS)

    Lim, Suk Young; Koh, Kwang Joon

    1993-01-01

    The purpose of this study was to clarify the spatial relationship of temporomandibular joint and to an aid in the diagnosis of temporomandibular disorder. For this study, three-dimensional images of normal temporomandibular joint were reconstructed by computer image analysis system and three-dimensional reconstructive program integrated in computed tomography. The obtained results were as follows : 1. Two-dimensional computed tomograms had the better resolution than three dimensional computed tomograms in the evaluation of bone structure and the disk of TMJ. 2. Direct sagittal computed tomograms and coronal computed tomograms had the better resolution in the evaluation of the disk of TMJ. 3. The positional relationship of the disk could be visualized, but the configuration of the disk could not be clearly visualized on three-dimensional reconstructive CT images. 4. Three-dimensional reconstructive CT images had the smoother margin than three-dimensional images reconstructed by computer image analysis system, but the images of the latter had the better perspective. 5. Three-dimensional reconstructive images had the better spatial relationship of the TMJ articulation, and the joint space were more clearly visualized on dissection images.

  18. Facial soft-tissue asymmetry in three-dimensional cone-beam computed tomography images of children with surgically corrected unilateral clefts.

    Science.gov (United States)

    Starbuck, John Marlow; Ghoneima, Ahmed; Kula, Katherine

    2014-03-01

    Cleft lip with or without cleft palate (CL/P) is a relatively common craniofacial malformation involving bony and soft-tissue disruptions of the nasolabial and dentoalveolar regions. The combination of CL/P and subsequent craniofacial surgeries to close the cleft and improve appearance of the cutaneous upper lip and nose can cause scarring and muscle pull, possibly resulting in soft-tissue depth asymmetries across the face. We tested the hypothesis that tissue depths in children with unilateral CL/P exhibit differences in symmetry across the sides of the face. Twenty-eight tissue depths were measured on cone-beam computed tomography images of children with unilateral CL/P (n = 55), aged 7 to 17 years, using Dolphin software (version 11.5). Significant differences in tissue depth symmetry were found around the cutaneous upper lip and nose in patients with unilateral CL/P.

  19. 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.

  20. Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

    International Nuclear Information System (INIS)

    Cordes, Nikolaus L.; Seshadri, Srivatsan; Havrilla, George J.; Yuan, Xiaoli; Feser, Michael; Patterson, Brian M.

    2015-01-01

    Current non-destructive elemental characterization methods, such as scanning electron microscopy-based energy dispersive spectroscopy (SEM–EDS) and micro-X-ray fluorescence spectroscopy (MXRF), are limited to either elemental identification at the surface (SEM–EDS) or suffer from an inability to discriminate between surface or depth information (MXRF). Thus, a non-destructive elemental characterization of individual embedded particles beneath the surface is impossible with either of these techniques. This limitation can be overcome by using laboratory-based 3D confocal micro-X-ray fluorescence spectroscopy (confocal MXRF). This technique utilizes focusing optics on the X-ray source and detector which allows for spatial discrimination in all three dimensions. However, the voxel-by-voxel serial acquisition of a 3D elemental scan can be very time-intensive (~ 1 to 4 weeks) if it is necessary to locate individual embedded particles of interest. As an example, if each point takes a 5 s measurement time, a small volume of 50 × 50 × 50 pixels leads to an acquisition time of approximately 174 h, not including sample stage movement time. Initially screening the samples for particles of interest using micro-X-ray computed tomography (micro-CT) can significantly reduce the time required to spatially locate these particles. Once located, these individual particles can be elementally characterized with confocal MXRF. Herein, we report the elemental identification of high atomic number surface and subsurface particles embedded in a mineralogical matrix by coupling micro-CT and confocal MXRF. Synergistically, these two X-ray based techniques first rapidly locate and then elementally identify individual subsurface particles. - Highlights: • Coupling of confocal X-ray fluorescence spectroscopy and X-ray computed tomography • Qualitative elemental identification of surface and subsurface mineral particles • Non-destructive particle size measurements • Utilization of

  1. Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, Nikolaus L., E-mail: ncordes@lanl.gov [Polymers and Coatings Group, Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Seshadri, Srivatsan, E-mail: srivatsan.seshadri@zeiss.com [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA 94588 (United States); Havrilla, George J. [Chemical Diagnostics and Engineering, Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Yuan, Xiaoli [Julius Kruttschnitt Mineral Research Centre, University of Queensland, Indooroopilly, Brisbane, QLD 4068 (Australia); Feser, Michael [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA 94588 (United States); Patterson, Brian M. [Polymers and Coatings Group, Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2015-01-01

    Current non-destructive elemental characterization methods, such as scanning electron microscopy-based energy dispersive spectroscopy (SEM–EDS) and micro-X-ray fluorescence spectroscopy (MXRF), are limited to either elemental identification at the surface (SEM–EDS) or suffer from an inability to discriminate between surface or depth information (MXRF). Thus, a non-destructive elemental characterization of individual embedded particles beneath the surface is impossible with either of these techniques. This limitation can be overcome by using laboratory-based 3D confocal micro-X-ray fluorescence spectroscopy (confocal MXRF). This technique utilizes focusing optics on the X-ray source and detector which allows for spatial discrimination in all three dimensions. However, the voxel-by-voxel serial acquisition of a 3D elemental scan can be very time-intensive (~ 1 to 4 weeks) if it is necessary to locate individual embedded particles of interest. As an example, if each point takes a 5 s measurement time, a small volume of 50 × 50 × 50 pixels leads to an acquisition time of approximately 174 h, not including sample stage movement time. Initially screening the samples for particles of interest using micro-X-ray computed tomography (micro-CT) can significantly reduce the time required to spatially locate these particles. Once located, these individual particles can be elementally characterized with confocal MXRF. Herein, we report the elemental identification of high atomic number surface and subsurface particles embedded in a mineralogical matrix by coupling micro-CT and confocal MXRF. Synergistically, these two X-ray based techniques first rapidly locate and then elementally identify individual subsurface particles. - Highlights: • Coupling of confocal X-ray fluorescence spectroscopy and X-ray computed tomography • Qualitative elemental identification of surface and subsurface mineral particles • Non-destructive particle size measurements • Utilization of

  2. Comparative Evaluation of a Four-Implant-Supported Polyetherketoneketone Framework Prosthesis: A Three-Dimensional Finite Element Analysis Based on Cone Beam Computed Tomography and Computer-Aided Design.

    Science.gov (United States)

    Lee, Ki-Sun; Shin, Sang-Wan; Lee, Sang-Pyo; Kim, Jong-Eun; Kim, Jee-Hwan; Lee, Jeong-Yol

    The purpose of this pilot study was to evaluate and compare polyetherketoneketone (PEKK) with different framework materials for implant-supported prostheses by means of a three-dimensional finite element analysis (3D-FEA) based on cone beam computed tomography (CBCT) and computer-aided design (CAD) data. A geometric model that consisted of four maxillary implants supporting a prosthesis framework was constructed from CBCT and CAD data of a treated patient. Three different materials (zirconia, titanium, and PEKK) were selected, and their material properties were simulated using FEA software in the generated geometric model. In the PEKK framework (ie, low elastic modulus) group, the stress transferred to the implant and simulated adjacent tissue was reduced when compressive stress was dominant, but increased when tensile stress was dominant. This study suggests that the shock-absorbing effects of a resilient implant-supported framework are limited in some areas and that rigid framework material shows a favorable stress distribution and safety of overall components of the prosthesis.

  3. Three dimensional optical coherence tomography imaging: advantages and advances.

    Science.gov (United States)

    Gabriele, Michelle L; Wollstein, Gadi; Ishikawa, Hiroshi; Xu, Juan; Kim, Jongsick; Kagemann, Larry; Folio, Lindsey S; Schuman, Joel S

    2010-11-01

    Three dimensional (3D) ophthalmic imaging using optical coherence tomography (OCT) has revolutionized assessment of the eye, the retina in particular. Recent technological improvements have made the acquisition of 3D-OCT datasets feasible. However, while volumetric data can improve disease diagnosis and follow-up, novel image analysis techniques are now necessary in order to process the dense 3D-OCT dataset. Fundamental software improvements include methods for correcting subject eye motion, segmenting structures or volumes of interest, extracting relevant data post hoc and signal averaging to improve delineation of retinal layers. In addition, innovative methods for image display, such as C-mode sectioning, provide a unique viewing perspective and may improve interpretation of OCT images of pathologic structures. While all of these methods are being developed, most remain in an immature state. This review describes the current status of 3D-OCT scanning and interpretation, and discusses the need for standardization of clinical protocols as well as the potential benefits of 3D-OCT scanning that could come when software methods for fully exploiting these rich datasets are available clinically. The implications of new image analysis approaches include improved reproducibility of measurements garnered from 3D-OCT, which may then help improve disease discrimination and progression detection. In addition, 3D-OCT offers the potential for preoperative surgical planning and intraoperative surgical guidance. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. Three-dimensional calibration targets for optical coherence tomography

    Science.gov (United States)

    Gabriele Sandrian, Michelle; Tomlins, Pete; Woolliams, Peter; Rasakanthan, Janarthanan; Lee, Graham C.; Yang, Anna; Považay, Boris; Alex, Aneesh; Sugden, Kate; Drexler, Wolfgang

    2012-03-01

    The recent expansion of clinical applications for optical coherence tomography (OCT) is driving the development of approaches for consistent image acquisition. There is a simultaneous need for time-stable, easy-to-use imaging targets for calibration and standardization of OCT devices. We present calibration targets consisting of three-dimensional structures etched into nanoparticle-embedded resin. Spherical iron oxide nanoparticles with a predominant particle diameter of 400 nm were homogeneously dispersed in a two part polyurethane resin and allowed to harden overnight. These samples were then etched using a precision micromachining femtosecond laser with a center wavelength of 1026 nm, 100kHz repetition rate and 450 fs pulse duration. A series of lines in depth were etched, varying the percentage of inscription energy and speed of the translation stage moving the target with respect to the laser. Samples were imaged with a dual wavelength spectral-domain OCT system (λ=800nm, ▵λ~180nm, and λ=1325nm, ▵λ~100nm) and point-spread function of nanoparticles within the target was measured.

  5. Diagnostic Value of Ex-Vivo Three-Dimensional Micro-Computed Tomography Imaging of Primary Nonhematopoietic Human Bone Tumors: Osteosarcoma versus Chondrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Langheinrich, A. C.; Stolle, C.; Kampschulte, M.; Lommel, D.; Rau, W. S.; Bassaly, B. (Depts. of Radiology and Pathology, Univ. of Giessen, Giessen (Germany))

    2008-10-15

    Background: Osteosarcoma and chondrosarcoma are the most common nonhematopoietic primary malignancies of bone. However, unusual radiographic appearances can lead to delay in diagnosis and confusion with benign diseases. Purpose: To evaluate the feasibility of micro-computed tomography (CT) for the analysis of primary, nonhematopoietic human bone tumors ex vivo. Material and Methods: Samples from 12 human bone specimens (osteosarcoma, n=6; chondrosarcoma, n=6) obtained for diagnostic purposes were scanned using industrial X-ray film without amplifier foil and scanned with micro-CT (7- and 12-mum-cubic voxels). Trabecular bone CT 'density' and tumor matrix CT 'density' were determined, and results were compared with those obtained from a detailed conventional histopathologic analysis of corresponding cross-sections. The significance of differences in grayscale measurements was tested with analysis of variance. Results: Micro-CT provided quantitative information on bone morphology equivalent to histopathological analysis. We established grayscale measurements by which tumor matrices of chondrosarcoma and osteosarcoma could be radiographically categorized following histological classifications (P<0.001). Conclusion: Micro-CT is feasible for the analysis and differentiation of human osteosarcoma and chondrosarcoma

  6. Adult Sex Identification Using Three-Dimensional Computed Tomography (3D-CT of the Pelvis: A Study Among a Sample of the Egyptian Population

    Directory of Open Access Journals (Sweden)

    Enas M. A. Mostafa

    2016-06-01

    Full Text Available Sex identification of unknown human skeletal remains is of great importance in establishing identity and individuality. In adults, the hip bone is the most reliable sex indicator because of its sexual dimorphism. Each population should have its own specific standards of identification. The objective of this study is to develop a logistic regression formula for adult sex identification using threedimensional computed tomography (3D-CT of the pelvis and to perform an assessment of its validity in sex determination among a sample of the Egyptian population in the Suez Canal region. 141 pelvic-abdominal CT images (free of any pelvic orthopaedic disorder were included; they were reconstructed to produce 3D-CT pelvic images which were divided into a calibration group (47 male and 47 female and a test group (47 CT images the sex of which was unknown to the observers. Twenty radiometric variables were measured for the calibration group. A logit response formula for sex prediction was developed and applied on the test group for sex prediction. The logit response formula for the test sample showed sensitivity, specificity, and an overall accuracy of 100%. The proposed method represents a quick and reliable metric method in establishing sex from a CT image of the pelvis bone.

  7. A novel region-growing based semi-automatic segmentation protocol for three-dimensional condylar reconstruction using cone beam computed tomography (CBCT.

    Directory of Open Access Journals (Sweden)

    Tong Xi

    Full Text Available OBJECTIVE: To present and validate a semi-automatic segmentation protocol to enable an accurate 3D reconstruction of the mandibular condyles using cone beam computed tomography (CBCT. MATERIALS AND METHODS: Approval from the regional medical ethics review board was obtained for this study. Bilateral mandibular condyles in ten CBCT datasets of patients were segmented using the currently proposed semi-automatic segmentation protocol. This segmentation protocol combined 3D region-growing and local thresholding algorithms. The segmentation of a total of twenty condyles was performed by two observers. The Dice-coefficient and distance map calculations were used to evaluate the accuracy and reproducibility of the segmented and 3D rendered condyles. RESULTS: The mean inter-observer Dice-coefficient was 0.98 (range [0.95-0.99]. An average 90th percentile distance of 0.32 mm was found, indicating an excellent inter-observer similarity of the segmented and 3D rendered condyles. No systematic errors were observed in the currently proposed segmentation protocol. CONCLUSION: The novel semi-automated segmentation protocol is an accurate and reproducible tool to segment and render condyles in 3D. The implementation of this protocol in the clinical practice allows the CBCT to be used as an imaging modality for the quantitative analysis of condylar morphology.

  8. 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

  9. Surgical Morphometry of C1 and C2 Vertebrae: A Three-Dimensional Computed Tomography Analysis of 180 Chinese, Indian, and Malay Patients.

    Science.gov (United States)

    Lee, Chee Kean; Tan, Tiam Siong; Chan, Chris Yin Wei; Kwan, Mun Keong

    2017-04-01

    Clinical imaging study. To study the surgical morphometry of C1 and C2 vertebrae in Chinese, Indian, and Malay patients. C1 lateral mass and C2 pedicle screw fixation is gaining popularity. However, there is a lack of C1-C2 morphometric data for the Asian population. Computed tomography analysis of 180 subjects (60 subjects each belonging to Chinese, Indian, and Malay populations) using simulation software was performed. Length and angulations of C1 lateral mass (C1LM) and C2 pedicle (C2P) screws were assessed. The predicted C1LM screw length was between 23.2 and 30.2 mm. The safe zone of trajectories was within 11.0°±7.7° laterally to 29.1°±6.2° medially in the axial plane and 37.0°±10.2° caudally to 20.9°±7.8° cephalically in the sagittal plane. The shortest and longest predicted C2P screw lengths were 22.1±2.8 mm and 28.5±3.2 mm, respectively. The safe trajectories were from 25.1° to 39.3° medially in the axial plane and 32.3° to 45.9° cephalically in the sagittal plane. C1LM screw length was 23-30 mm with the axial safe zone from 11° laterally to 29° medially and sagittal safe zone at 21° cephalically. C2P screw length was 22-28 mm with axial safe zone from 26° to 40° medially and sagittal safe zone from 32° to 46° cephalically. These data serve as an important reference for Chinese, Indian, and Malay populations during C1-C2 instrumentation.

  10. Particle coagulation in molten metal based on three-dimensional analysis of cluster by x-ray micro-computer tomography (CT)

    International Nuclear Information System (INIS)

    Li, Tao; Shimasaki, Shin-ichi; Taniguchi, Shoji; Narita, Shunsuke; Uesugi, Kentaro

    2013-01-01

    Particle coagulation plays a key role in steel refining process to remove inclusions. Many research works focus on the behaviors of particle coagulation. To reveal its mechanism water model experiments have been performed by some researchers including the authors' group. In this paper, experiments of particle coagulation were carried out with molten Al including SiC particles in a mechanically agitated crucible with two baffles. Particle coagulation and formation of clusters were observed on the microscopy images of as-polished samples. Three-dimensional (3D) analysis of the clusters in solidified Al was implemented by X-ray micro CT available at SPring-8. The methods to distinguish clusters on two-dimensional (2D) cross-sectional images were discussed, which were established in the previous works by the present authors' group. The characteristics of the 3D SiC clusters and their 2D cross-sections were analyzed. The statistical ranges of the parameters for 2D clusters were used as criterions to distinguish the clusters on 2D microscopy images from the as-polished samples. The kinetics of SiC particle coagulation was studied by the measured cluster number density and size using our program to distinguish cluster in 2D cross-sectional images according to 3D information (DC-2D-3D). The calculated and experimental results of the SiC particle coagulation in molten Al agree well with each other. (author)

  11. Prospective randomized comparison of rotational angiography with three-dimensional reconstruction and computed tomography merged with electro-anatomical mapping: a two center atrial fibrillation ablation study.

    Science.gov (United States)

    Anand, Rishi; Gorev, Maxim V; Poghosyan, Hermine; Pothier, Lindsay; Matkins, John; Kotler, Gregory; Moroz, Sarah; Armstrong, James; Nemtsov, Sergei V; Orlov, Michael V

    2016-08-01

    To compare the efficacy and accuracy of rotational angiography with three-dimensional reconstruction (3DATG) image merged with electro-anatomical mapping (EAM) vs. CT-EAM. A prospective, randomized, parallel, two-center study conducted in 36 patients (25 men, age 65 ± 10 years) undergoing AF ablation (33 % paroxysmal, 67 % persistent) guided by 3DATG (group 1) vs. CT (group 2) image fusion with EAM. 3DATG was performed on the Philips Allura Xper FD 10 system. Procedural characteristics including time, radiation exposure, outcome, and navigation accuracy were compared between two groups. There was no significant difference between the groups in total procedure duration or time spent for various procedural steps. Minor differences in procedural characteristics were present between two centers. Segmentation and fusion time for 3DATG or CT-EAM was short and similar between both centers. Accuracy of navigation guided by either method was high and did not depend on left atrial size. Maintenance of sinus rhythm between the two groups was no different up to 24 months of follow-up. This study did not find superiority of 3DATG-EAM image merge to guide AF ablation when compared to CT-EAM fusion. Both merging techniques result in similar navigation accuracy.

  12. Refinement of Treatment Setup and Target Localization Accuracy Using Three-Dimensional Cone-Beam Computed Tomography for Stereotactic Body Radiotherapy

    International Nuclear Information System (INIS)

    Wang Zhiheng; Nelson, John W.; Yoo, Sua; Wu, Q. Jackie; Kirkpatrick, John P.; Marks, Lawrence B.; Yin Fangfang

    2009-01-01

    Purposes: To quantitatively compare two-dimensional (2D) orthogonal kV with three-dimensional (3D) cone-beam CT (CBCT) for target localization; and to assess intrafraction motion with kV images in patients undergoing stereotactic body radiotherapy (SBRT). Methods and Materials: A total of 50 patients with 58 lesions received 178 fractions of SBRT. After clinical setup using in-room lasers and skin/cradle marks placed at simulation, patients were imaged and repositioned according to orthogonal kV/MV registration of bony landmarks to digitally reconstructed radiographs from the planning CT. A subsequent CBCT was registered to the planning CT using soft tissue information, and the resultant 'residual error' was measured and corrected before treatment. Posttreatment 2D kV and/or 3D CBCT images were compared with pretreatment images to determine any intrafractional position changes. Absolute averages, statistical means, standard deviations, and root mean square (RMS) values of observed setup error were calculated. Results: After initial setup to external marks with laser guidance, 2D kV images revealed vector mean setup deviations of 0.67 cm (RMS). Cone-beam CT detected residual setup deviations of 0.41 cm (RMS). Posttreatment imaging demonstrated intrafractional variations of 0.15 cm (RMS). The individual shifts in three standard orthogonal planes showed no obvious directional biases. Conclusions: After localization based on superficial markings in patients undergoing SBRT, orthogonal kV imaging detects setup variations of approximately 3 to 4 mm in each direction. Cone-beam CT detects residual setup variations of approximately 2 to 3 mm

  13. Sensitivity analysis for plane orientation in three-dimensional cephalometric analysis based on superimposition of serial cone beam computed tomography images

    Science.gov (United States)

    Lagravère, M O; Major, P W; Carey, J

    2010-01-01

    Objectives The purpose of this study was to evaluate the potential errors associated with superimposition of serial cone beam CT (CBCT) images utilizing reference planes based on cranial base landmarks using a sensitivity analysis. Methods CBCT images from 62 patients participating in a maxillary expansion clinical trial were analysed. The left and right auditory external meatus (AEM), dorsum foramen magnum (DFM) and the midpoint between the left and right foramen spinosum (ELSA) were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Intraclass correlation coefficients for all four landmarks were obtained. Transformation of the reference system was carried out using the four landmarks and mathematical comparison of values. Results Excellent intrareliability values for each dimension were obtained for each landmark. Evaluation of the method to transform the co-ordinate system was first done by comparing interlandmark distances before and after transformations, giving errors in lengths in the order of 10–14% (software rounding error). A sensitivity evaluation was performed by adding 0.25 mm, 0.5 mm and 1 mm error in one axis of the ELSA. A positioning error of 0.25 mm in the ELSA can produce up to 1.0 mm error in other cranial base landmark co-ordinates. These errors could be magnified to distant landmarks where in some cases menton and infraorbital landmarks were displaced 4–6 mm. Conclusions Minor variations in location of the ELSA, both the AEM and the DFM landmarks produce large and potentially clinically significant uncertainty in co-ordinate system alignment. PMID:20841457

  14. A method for three-dimensional analysis of the root canal system, before and after mechanical instrumentation, using X-ray Micro-computed tomography

    DEFF Research Database (Denmark)

    Markvart, Merete; Bjørndal, Lars; Larsen, Per

    . Extracted molar teeth were embedded in resin and kept moisturized. Each root canal was instrumented with NiTi instruments to #40. The teeth were scanned before and after instrumentation, using a microCT40 micro-tomography (SCANCO Medical AG, Bassersdorf, Switzerland). The reconstructed slices were imported......Clinical studies have shown a connection between the reduction of micro-organisms in the root canal and the degree of apical enlargement. The aim of this study was to create a non-invasive 3D model for monitoring the apical enlargement in molar teeth before and after mechanical instrumentation...

  15. Mathematical modeling of three-dimensional images in emission tomography

    International Nuclear Information System (INIS)

    Koblik, Yu.N.; Khugaev, A. V.; Mktchyan, G.A.; Ioannou, P.; Dimovasili, E.

    2002-01-01

    The model of processing results of three-dimensional measurements in positron-emissive tomograph is proposed in this work. The algorithm of construction and visualization of phantom objects of arbitrary shape was developed and its concrete realization in view of program packet for PC was carried out

  16. Three-dimensional computerized tomography in mandibular condyle fractures

    International Nuclear Information System (INIS)

    Bermeo, Fausto; Salazar, Abad

    2003-01-01

    Now, car accidents are so commons, this associated to the high technology in produce automobiles make this type of accidents so serious and the consequences of mandibular condyle fractures are more commons and with more gravity, some of these patients, generally need a traqueostomy to be operated, that is why every second that we can save during the surgery is important. The normal exams as X rays and simple TAC give as an important idea but no complete, on the contrary the three-dimensional TAC permits to observe every damages and its exact location, this contribute to make a better surgery organization, the number and type of plates that we have to put and the better way to treat each case, that contribute to reduce time in operating theatre which is in benefit of the patient, diminishing risks in serious patients as they are, that is why we recommend the utilization of the three-dimensional TAC. (The author)

  17. Three-dimensional integrated CAE system applying computer graphic technique

    International Nuclear Information System (INIS)

    Kato, Toshisada; Tanaka, Kazuo; Akitomo, Norio; Obata, Tokayasu.

    1991-01-01

    A three-dimensional CAE system for nuclear power plant design is presented. This system utilizes high-speed computer graphic techniques for the plant design review, and an integrated engineering database for handling the large amount of nuclear power plant engineering data in a unified data format. Applying this system makes it possible to construct a nuclear power plant using only computer data from the basic design phase to the manufacturing phase, and it increases the productivity and reliability of the nuclear power plants. (author)

  18. A three-dimensional computed tomography-assisted Monte Carlo evaluation of ovoid shielding on the dose to the bladder and rectum in intracavitary radiotherapy for cervical cancer

    International Nuclear Information System (INIS)

    Gifford, Kent A.; Horton, John L.; Pelloski, Christopher E.; Jhingran, Anuja; Court, Laurence E.; Mourtada, Firas; Eifel, Patricia J.

    2005-01-01

    Purpose: To determine the effects of Fletcher Suit Delclos ovoid shielding on dose to the bladder and rectum during intracavitary radiotherapy for cervical cancer. Methods and Materials: The Monte Carlo method was used to calculate the dose in 12 patients receiving low-dose-rate intracavitary radiotherapy with both shielded and unshielded ovoids. Cumulative dose-difference surface histograms were computed for the bladder and rectum. Doses to the 2-cm 3 and 5-cm 3 volumes of highest dose were computed for the bladder and rectum with and without shielding. Results: Shielding affected dose to the 2-cm 3 and 5-cm 3 volumes of highest dose for the rectum (10.1% and 11.1% differences, respectively). Shielding did not have a major impact on the dose to the 2-cm 3 and 5-cm 3 volumes of highest dose for the bladder. The average dose reduction to 5% of the surface area of the bladder was 53 cGy. Reductions as large as 150 cGy were observed to 5% of the surface area of the bladder. The average dose reduction to 5% of the surface area of the rectum was 195 cGy. Reductions as large as 405 cGy were observed to 5% of the surface area of the rectum. Conclusions: Our data suggest that the ovoid shields can greatly reduce the radiation dose delivered to the rectum. We did not find the same degree of effect on the dose to the bladder. To calculate the dose accurately, however, the ovoid shields must be included in the dose model

  19. Three-dimensional computer graphics for surgical procedure learning: Web three-dimensional application for cleft lip repair.

    Science.gov (United States)

    Kobayashi, Masahiro; Nakajima, Tatsuo; Mori, Ayako; Tanaka, Daigo; Fujino, Toyomi; Chiyokura, Hiroaki

    2006-05-01

    In surgical procedures for cleft lip, surgeons attempt to use various skin incisions and small flaps to achieve a better and more natural shape postoperatively. They must understand the three-dimensional (3D) structure of the lips. However, they may have difficulty learning the surgical procedures precisely from normal textbooks with two-dimensional illustrations. Recent developments in 3D computed tomography (3D-CT) and laser stereolithography have enabled surgeons to visualize the structures of cleft lips from desired viewpoints. However, this method cannot reflect the advantages offered by specific surgical procedures. To solve this problem, we used the benefits offered by 3D computer graphics (3D-CG) and 3D animation. By using scanning 3D-CT image data of patients with cleft lips, 3D-CG models of the cleft lips were created. Several animations for surgical procedures such as incision designs, rotation of small skin flaps, and sutures were made. This system can recognize the details of an operation procedure clearly from any viewpoint, which cannot be acquired from the usual textbook illustrations. This animation system can be used for developing new skin-flap design, understanding the operational procedure, and using tools in case presentations. The 3D animations can also be uploaded to the World Wide Web for use in teleconferencing.

  20. Three-Dimensional Liver Surgery Simulation: Computer-Assisted Surgical Planning with Three-Dimensional Simulation Software and Three-Dimensional Printing.

    Science.gov (United States)

    Oshiro, Yukio; Ohkohchi, Nobuhiro

    2017-06-01

    To perform accurate hepatectomy without injury, it is necessary to understand the anatomical relationship among the branches of Glisson's sheath, hepatic veins, and tumor. In Japan, three-dimensional (3D) preoperative simulation for liver surgery is becoming increasingly common, and liver 3D modeling and 3D hepatectomy simulation by 3D analysis software for liver surgery have been covered by universal healthcare insurance since 2012. Herein, we review the history of virtual hepatectomy using computer-assisted surgery (CAS) and our research to date, and we discuss the future prospects of CAS. We have used the SYNAPSE VINCENT medical imaging system (Fujifilm Medical, Tokyo, Japan) for 3D visualization and virtual resection of the liver since 2010. We developed a novel fusion imaging technique combining 3D computed tomography (CT) with magnetic resonance imaging (MRI). The fusion image enables us to easily visualize anatomic relationships among the hepatic arteries, portal veins, bile duct, and tumor in the hepatic hilum. In 2013, we developed an original software, called Liversim, which enables real-time deformation of the liver using physical simulation, and a randomized control trial has recently been conducted to evaluate the use of Liversim and SYNAPSE VINCENT for preoperative simulation and planning. Furthermore, we developed a novel hollow 3D-printed liver model whose surface is covered with frames. This model is useful for safe liver resection, has better visibility, and the production cost is reduced to one-third of a previous model. Preoperative simulation and navigation with CAS in liver resection are expected to help planning and conducting a surgery and surgical education. Thus, a novel CAS system will contribute to not only the performance of reliable hepatectomy but also to surgical education.

  1. [Three-dimensional computer aided design for individualized post-and-core restoration].

    Science.gov (United States)

    Gu, Xiao-yu; Wang, Ya-ping; Wang, Yong; Lü, Pei-jun

    2009-10-01

    To develop a method of three-dimensional computer aided design (CAD) of post-and-core restoration. Two plaster casts with extracted natural teeth were used in this study. The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models. According to the basic rules of post-and-core design, posts, cores and cavity surfaces of the teeth were designed using the tools for processing point clouds, curves and surfaces on the forward engineering software of Tanglong prosthodontic system. Then three-dimensional figures of the final restorations were corrected according to the configurations of anterior teeth, premolars and molars respectively. Computer aided design of 14 post-and-core restorations were finished, and good fitness between the restoration and the three-dimensional digital models were obtained. Appropriate retention forms and enough spaces for the full crown restorations can be obtained through this method. The CAD of three-dimensional figures of the post-and-core restorations can fulfill clinical requirements. Therefore they can be used in computer-aided manufacture (CAM) of post-and-core restorations.

  2. Three-dimensional protein structure prediction: Methods and computational strategies.

    Science.gov (United States)

    Dorn, Márcio; E Silva, Mariel Barbachan; Buriol, Luciana S; Lamb, Luis C

    2014-10-12

    A long standing problem in structural bioinformatics is to determine the three-dimensional (3-D) structure of a protein when only a sequence of amino acid residues is given. Many computational methodologies and algorithms have been proposed as a solution to the 3-D Protein Structure Prediction (3-D-PSP) problem. These methods can be divided in four main classes: (a) first principle methods without database information; (b) first principle methods with database information; (c) fold recognition and threading methods; and (d) comparative modeling methods and sequence alignment strategies. Deterministic computational techniques, optimization techniques, data mining and machine learning approaches are typically used in the construction of computational solutions for the PSP problem. Our main goal with this work is to review the methods and computational strategies that are currently used in 3-D protein prediction. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Three-dimensional S-wave tomography under Axial Seamount

    Science.gov (United States)

    Baillard, C.; Wilcock, W. S. D.; Arnulf, A. F.; Tolstoy, M.; Waldhauser, F.

    2017-12-01

    Axial Seamount is a submarine volcano located at the intersection of the Juande Fuca Ridge and the Cobb-Eickelberg hotspot 500 km off the coast of thenorthwestern United States. The seamount, which rises 1 km above the seafloor, ischaracterized by a shallow caldera that is elongated in the N-S direction, measure 8km by 3 km and sits on top of a 14 km by 3 km magma reservoir. Two eruptive eventsin 1998 and 2011 motivated the deployment in 2014 of a real time cabled observatorywithin the Axial caldera, as part of the Ocean Observatories Initiative (OOI).Theobservatory includes a network of seven seismometers that span the southern half ofthe caldera. Five months after the observatory came on-line in November 2014, thevolcano erupted on April 24, 2015. Well over 100,000 events were located in thevicinity of the caldera, delineating an outward dipping ring fault that extends fromnear the surface to the magma body at 2 km depth and which accommodatesinflation and deflation of the volcano.The initial earthquake locations have beenobtained with a one-dimensional velocity model but the travel time residuals suggeststrong heterogeneities. A three-dimensional P-wave velocity model, obtained bycombining multichannel and ocean bottom seismometer refraction data, is being usedto refine locations but the three-dimensional S-wave structure is presently unknown.In most mid-ocean ridge settings, the distribution of earthquakes is not conducive forjoint inversions for S-wave velocity and hypocentral parameters because there are fewcrossing ray paths but at Axial the presence of a ring fault that is seismically active atall depths on both the east and west side of the caldera, provides a reasonablegeometry for such efforts. We will present the results of joint inversions that assumethe existing three-dimensional P wave velocity model and solve for VP/VS structure andhypocentral parameters using LOTOS, an algorithm that solves the forward problemusing ray bending.The resulting model

  4. Three-dimensional observation of TiO2 nanostructures by electron tomography

    KAUST Repository

    Suh, Young Joon; Lu, Ning; Park, Seong Yong; Lee, Tae Hun; Lee, Sang Hoon; Cha, Dong Kyu; Lee, Min Gun; Huang, Jie; Kim, Sung Soo; Sohn, Byeong Hyeok; Kim, Geung Ho; Ko, Min Jae; Kim, Jiyoung; Kim, Moon J.

    2013-01-01

    Three-dimensional nanostructures of TiO2 related materials including nanotubes, electron acceptor materials in hybrid polymer solar cells, and working electrodes of dye sensitized solar cells (DSSCs) were visualized by electron tomography as well

  5. ANS main control complex three-dimensional computer model development

    International Nuclear Information System (INIS)

    Cleaves, J.E.; Fletcher, W.M.

    1993-01-01

    A three-dimensional (3-D) computer model of the Advanced Neutron Source (ANS) main control complex is being developed. The main control complex includes the main control room, the technical support center, the materials irradiation control room, computer equipment rooms, communications equipment rooms, cable-spreading rooms, and some support offices and breakroom facilities. The model will be used to provide facility designers and operations personnel with capabilities for fit-up/interference analysis, visual ''walk-throughs'' for optimizing maintain-ability, and human factors and operability analyses. It will be used to determine performance design characteristics, to generate construction drawings, and to integrate control room layout, equipment mounting, grounding equipment, electrical cabling, and utility services into ANS building designs. This paper describes the development of the initial phase of the 3-D computer model for the ANS main control complex and plans for its development and use

  6. Three-dimensional photoacoustic tomography based on graphics-processing-unit-accelerated finite element method.

    Science.gov (United States)

    Peng, Kuan; He, Ling; Zhu, Ziqiang; Tang, Jingtian; Xiao, Jiaying

    2013-12-01

    Compared with commonly used analytical reconstruction methods, the frequency-domain finite element method (FEM) based approach has proven to be an accurate and flexible algorithm for photoacoustic tomography. However, the FEM-based algorithm is computationally demanding, especially for three-dimensional cases. To enhance the algorithm's efficiency, in this work a parallel computational strategy is implemented in the framework of the FEM-based reconstruction algorithm using a graphic-processing-unit parallel frame named the "compute unified device architecture." A series of simulation experiments is carried out to test the accuracy and accelerating effect of the improved method. The results obtained indicate that the parallel calculation does not change the accuracy of the reconstruction algorithm, while its computational cost is significantly reduced by a factor of 38.9 with a GTX 580 graphics card using the improved method.

  7. Three-dimensional computer aided design system for plant layout

    International Nuclear Information System (INIS)

    Yoshinaga, Toshiaki; Kiguchi, Takashi; Tokumasu, Shinji; Kumamoto, Kenjiro.

    1986-01-01

    The CAD system for three-dimensional plant layout planning, with which the layout of pipings, cable trays, air conditioning ducts and so on in nuclear power plants can be planned and designed effectively in a short period is reported. This system comprises the automatic routing system by storing the rich experience and know-how of designers in a computer as the knowledge, and deciding the layout automatically following the predetermined sequence by using these, the interactive layout system for reviewing the routing results from higher level and modifying to the optimum layout, the layout evaluation system for synthetically evaluating the layout from the viewpoint of the operability such as checkup and maintenance, and the data base system which enables these effective planning and design. In this report, the total constitution of this system and the technical features and effects of the individual subsystems are outlined. In this CAD system for three-dimensional plant layout planning, knowledge engineering, CAD/CAM, computer graphics and other latest technology were introduced, accordingly by applying this system to plant design, the design can be performed quickly, various case studies can be carried out at planning stage, and systematic and optimum layout planning becomes possible. (Kako, I.)

  8. Automated Defect Recognition as a Critical Element of a Three Dimensional X-ray Computed Tomography Imaging-Based Smart Non-Destructive Testing Technique in Additive Manufacturing of Near Net-Shape Parts

    Directory of Open Access Journals (Sweden)

    Istvan Szabo

    2017-11-01

    Full Text Available In this paper, a state of the art automated defect recognition (ADR system is presented that was developed specifically for Non-Destructive Testing (NDT of powder metallurgy (PM parts using three dimensional X-ray Computed Tomography (CT imaging, towards enabling online quality assurance and enhanced integrity confidence. PM parts exhibit typical defects such as microscopic cracks, porosity, and voids, internal to components that without an effective detection system, limit the growth of industrial applications. Compared to typical testing methods (e.g., destructive such as metallography that is based on sampling, cutting, and polishing of parts, CT provides full coverage of defect detection. This paper establishes the importance and advantages of an automated NDT system for the PM industry applications with particular emphasis on image processing procedures for defect recognition. Moreover, the article describes how to establish a reference library based on real 3D X-ray CT images of net-shape parts. The paper follows the development of the ADR system from processing 2D image slices of a measured 3D X-ray image to processing the complete 3D X-ray image as a whole. The introduced technique is successfully integrated into an automated in-line quality control system highly sought by major industry sectors in Oil and Gas, Automotive, and Aerospace.

  9. Three-dimensional (3D)- computed tomography bronchography and angiography combined with 3D-video-assisted thoracic surgery (VATS) versus conventional 2D-VATS anatomic pulmonary segmentectomy for the treatment of non-small cell lung cancer.

    Science.gov (United States)

    She, Xiao-Wei; Gu, Yun-Bin; Xu, Chun; Li, Chang; Ding, Cheng; Chen, Jun; Zhao, Jun

    2018-02-01

    Compared to the pulmonary lobe, the anatomical structure of the pulmonary segment is relatively complex and prone to variation, thus the risk and difficulty of segmentectomy is increased. We compared three-dimensional computed tomography bronchography and angiography (3D-CTBA) combined with 3D video-assisted thoracic surgery (3D-VATS) to perform segmentectomy to conventional two-dimensional (2D)-VATS for the treatment of non-small cell lung cancer (NSCLC). We retrospectively reviewed the data of randomly selected patients who underwent 3D-CTBA combined with 3D-VATS (3D-CTBA-VATS) or 2D-VATS at the Department of Thoracic Surgery, The First Affiliated Hospital of Soochow University Hospital, from January 2014 to May 2017. The operative duration of 3D group was significantly shorter than the 2D group (P 0.05). The extent of intraoperative bleeding and postoperative drainage in the 3D group was significantly lower than in the 2D group (P 3D group was shorter than in the 2D group (P 0.05). However, hemoptysis and pulmonary air leakage (>3d) occurred significantly less frequently in the 3D than in the 2D group (P 3D-CTBA-VATS is a more accurate and smooth technique and leads to reduced intraoperative and postoperative complications. © 2018 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

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

    Science.gov (United States)

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

    2017-12-01

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

  11. A three-dimensional magnetostatics computer code for insertion devices

    International Nuclear Information System (INIS)

    Chubar, O.; Elleaume, P.; Chavanne, J.

    1998-01-01

    RADIA is a three-dimensional magnetostatics computer code optimized for the design of undulators and wigglers. It solves boundary magnetostatics problems with magnetized and current-carrying volumes using the boundary integral approach. The magnetized volumes can be arbitrary polyhedrons with non-linear (iron) or linear anisotropic (permanent magnet) characteristics. The current-carrying elements can be straight or curved blocks with rectangular cross sections. Boundary conditions are simulated by the technique of mirroring. Analytical formulae used for the computation of the field produced by a magnetized volume of a polyhedron shape are detailed. The RADIA code is written in object-oriented C++ and interfaced to Mathematica (Mathematica is a registered trademark of Wolfram Research, Inc.). The code outperforms currently available finite-element packages with respect to the CPU time of the solver and accuracy of the field integral estimations. An application of the code to the case of a wedge-pole undulator is presented

  12. Three-Dimensional Seismic Tomography Beneath Tangshan, China

    Science.gov (United States)

    Chang, J. C.; Keranen, K. M.; Keller, G.; Qu, G.; Harder, S. H.

    2010-12-01

    The 1976 earthquake in Tangshan, China ranks as the deadliest earthquake in modern times. Though the exact number of casualties remains disputed, it is widely accepted that at least a quarter of a million people died. The high casualty level is surprising since the earthquake was not unusually large (Mw 7.5). Amplification of ground motion by thick sediment fill in the basin underlying the city is a likely cause for the extensive destruction. However, the extent of the unconsolidated material and the broader subsurface geology beneath Tangshan and surrounding areas needs to be better-constrained to properly model predicted ground motion and mitigate the hazards of future earthquakes. From a broader perspective, the Tangshan area is at the northern edge of the Bohai Bay basin province that has experienced both Cenozoic extension and related strike-slip tectonism. In January 2010, our group conducted a three-dimensional seismic investigation centered on the city of Tangshan. In an area of approximately 40 km x 60 km, we deployed 500 REFTEK 125A (“Texan”) recorders at 500 m spacing. A number of different sources, 20 altogether, were recorded during the two-day listening window, which include our large shots, smaller explosive shots from a co-spatial reflection survey, blasts from nearby quarries, and a small (Mearthquake. Our preliminary analyses suggest that the sediment fill is, on average, less than 1 km thick. Sediment fill is thinner to the north, as evidenced by outcropping bedrock, and thickens to the south. Sediment seismic velocity is about 1.8 km/s. Upper crustal velocities are 5.2 to 6.6 km/s, and increase to 7.0 km/s at mid-crustal depths.

  13. 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

  14. Positron Emission Tomography with Three-Dimensional Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Erlandsson, K.

    1996-10-01

    The development of two different low-cost scanners for positron emission tomography (PET) based on 3D acquisition are presented. The first scanner consists of two rotating scintillation cameras, and produces quantitative images, which have shown to be clinically useful. The second one is a system with two opposed sets of detectors, based on the limited angle tomography principle, dedicated for mammographic studies. The development of low-cost PET scanners can increase the clinical impact of PET, which is an expensive modality, only available at a few centres world-wide and mainly used as a research tool. A 3D reconstruction method was developed that utilizes all the available data. The size of the data-sets is considerably reduced, using the single-slice rebinning approximation. The 3D reconstruction is divided into 1D axial deconvolution and 2D transaxial reconstruction, which makes it relatively fast. This method was developed for the rotating scanner, but was also implemented for multi-ring scanners with and without inter plane septa. An iterative 3D reconstruction method was developed for the limited angle scanner, based on the new concept of `mobile pixels`, which reduces the finite pixel errors and leads to an improved signal to noise ratio. 100 refs.

  15. Positron Emission Tomography with Three-Dimensional Reconstruction

    International Nuclear Information System (INIS)

    Erlandsson, K.

    1996-10-01

    The development of two different low-cost scanners for positron emission tomography (PET) based on 3D acquisition are presented. The first scanner consists of two rotating scintillation cameras, and produces quantitative images, which have shown to be clinically useful. The second one is a system with two opposed sets of detectors, based on the limited angle tomography principle, dedicated for mammographic studies. The development of low-cost PET scanners can increase the clinical impact of PET, which is an expensive modality, only available at a few centres world-wide and mainly used as a research tool. A 3D reconstruction method was developed that utilizes all the available data. The size of the data-sets is considerably reduced, using the single-slice rebinning approximation. The 3D reconstruction is divided into 1D axial deconvolution and 2D transaxial reconstruction, which makes it relatively fast. This method was developed for the rotating scanner, but was also implemented for multi-ring scanners with and without inter plane septa. An iterative 3D reconstruction method was developed for the limited angle scanner, based on the new concept of 'mobile pixels', which reduces the finite pixel errors and leads to an improved signal to noise ratio. 100 refs

  16. [Three dimensional CT reconstruction system on a personal computer].

    Science.gov (United States)

    Watanabe, E; Ide, T; Teramoto, A; Mayanagi, Y

    1991-03-01

    A new computer system to produce three dimensional surface image from CT scan has been invented. Although many similar systems have been already developed and reported, they are too expensive to be set up in routine clinical services because most of these systems are based on high power mini-computer systems. According to the opinion that a practical 3D-CT system should be used in daily clinical activities using only a personal computer, we have transplanted the 3D program into a personal computer working in MS-DOS (16-bit, 12 MHz). We added to the program a routine which simulates surgical dissection on the surface image. The time required to produce the surface image ranges from 40 to 90 seconds. To facilitate the simulation, we connected a 3D system with the neuronavigator. The navigator gives the position of the surgical simulation when the surgeon places the navigator tip on the patient's head thus simulating the surgical excision before the real dissection.

  17. Three-dimensional STIM tomography and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Cholewa, M; Saint, A; Prawer, S; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Stuart, S A [CSIRO, Clayton, VIC (Australia). Forest Product Div.; Howard, J [Australian National Univ., Canberra, ACT (Australia). Plasma Research Lab.

    1994-12-31

    Scanning Transmission Microscopy (STIM) tomography was used to characterize bulk density variation in CVD diamonds. To maintain submicron resolution in the tomographic data, several factors need to be considered: (a) precise sample manipulation, (b) control of the quality of a detector, (c) beam spreading while traversing the sample and (d) change of stopping power with the energy. The influence of these factors would be addressed in this paper. It is also shown that the method was capable of coping with large and small density variations within the one specimen. These density variations have been shown to vary between disordered carbon ({approx} 2 g/cm{sup 3}), diamond ({approx} 3.2 g/cm{sup 3}) and tungsten ({approx} 19.6 g/cm{sup 3}), all in one specimen. 5 refs., 2 figs.

  18. Three-dimensional STIM tomography and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Cholewa, M.; Saint, A.; Prawer, S.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Stuart, S.A. [CSIRO, Clayton, VIC (Australia). Forest Product Div.; Howard, J. [Australian National Univ., Canberra, ACT (Australia). Plasma Research Lab.

    1993-12-31

    Scanning Transmission Microscopy (STIM) tomography was used to characterize bulk density variation in CVD diamonds. To maintain submicron resolution in the tomographic data, several factors need to be considered: (a) precise sample manipulation, (b) control of the quality of a detector, (c) beam spreading while traversing the sample and (d) change of stopping power with the energy. The influence of these factors would be addressed in this paper. It is also shown that the method was capable of coping with large and small density variations within the one specimen. These density variations have been shown to vary between disordered carbon ({approx} 2 g/cm{sup 3}), diamond ({approx} 3.2 g/cm{sup 3}) and tungsten ({approx} 19.6 g/cm{sup 3}), all in one specimen. 5 refs., 2 figs.

  19. Effects of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex after hamstring harvesting for anterior cruciate ligament reconstruction. Evaluation using three-dimensional computed tomography

    International Nuclear Information System (INIS)

    Nakamae, Atsuo; Adachi, Nobuo; Nakasa, Tomoyuki; Nishimori, Makoto; Ochi, Mitsuo; Deie, Masataka

    2012-01-01

    It is desirable to maintain the morphology of the semitendinosus muscle-tendon complex after tendon harvesting for anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the effect of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex. In total, 39 patients who underwent ACL reconstruction with autologous semitendinosus tendons were included in this study. After surgery, the knee was immobilized for 3 days in 1 group of patients (group 1; 24 patients; control group) and for a longer period (10-14 days) in the other group (group 2; 15 patients). Three-dimensional computed tomography (3D CT) examination was performed at 6 and/or 12 months after the surgery for all patients. Morphological changes in the semitendinosus muscle-tendon complex (proximal shift of the semitendinosus muscle-tendon junction, width of the regenerated semitendinosus tendons, re-insertion sites of the regenerated tendons, and rate of semitendinosus tendon regeneration) were evaluated. Successful regeneration of the semitendinosus tendon was confirmed in all patients in group 2. In group 1, 3D CT showed that regeneration of the semitendinosus tendon was unsuccessful in 1 of the 24 patients. The average length of the proximal shift of the semitendinosus muscle-tendon junction was 7.3±2.5 cm in group 1 and 7.2±1.9 cm in group 2. There were no significant differences between the 2 groups with regard to the morphological changes in the semitendinosus muscle-tendon complex. This study showed that the structure of regenerated tendons could be clearly identified in 38 of 39 cases (97.4%) after ACL reconstruction. However, prolonged knee immobilization (10-14 days) could not prevent morphological changes in the semitendinosus muscle-tendon complex. (author)

  20. Three-dimensional reconstructed computed tomography-magnetic resonance fusion image-based preoperative planning for surgical procedures for spinal lipoma or tethered spinal cord after myelomeningocele repair. Technical note

    International Nuclear Information System (INIS)

    Bamba, Yohei; Nonaka, Masahiro; Nakajima, Shin; Yamasaki, Mami

    2011-01-01

    Surgical procedures for spinal lipoma or tethered spinal cord after myelomeningocele (MMC) repair are often difficult and complicated, because the anatomical structures can be deformed in complex and unpredictable ways. Imaging helps the surgeon understand the patient's spinal anatomy. Whereas two-dimensional images provide only limited information for surgical planning, three-dimensional (3D) reconstructed computed tomography (CT)-magnetic resonance (MR) fusion images produce clearer representations of the spinal regions. Here we describe simple and quick methods for obtaining 3D reconstructed CT-MR fusion images for preoperative planning of surgical procedures using the iPlan cranial (BrainLAB AG, Feldkirchen, Germany) neuronavigation software. 3D CT images of the vertebral bone were combined with heavily T 2 -weighted MR images of the spinal cord, lipoma, cerebrospinal fluid (CSF) space, and nerve root through a process of fusion, segmentation, and reconstruction of the 3D images. We also used our procedure called 'Image Overlay' to directly project the 3D reconstructed image onto the body surface using an light emitting diode (LED) projector. The final reconstructed 3D images took 10-30 minutes to obtain, and provided the surgeon with a representation of the individual pathological structures, so enabled the design of effective surgical plans, even in patients with bony deformity such as scoliosis. None of the 19 patients treated based on our 3D reconstruction method has had neurological complications, except for CSF leakage. This 3D reconstructed imaging method, combined with Image Overlay, improves the visual understanding of complicated surgical situations, and should improve surgical efficiency and outcome. (author)

  1. Neurosurgical simulation and navigation with three-dimensional computer graphics.

    Science.gov (United States)

    Hayashi, N; Endo, S; Shibata, T; Ikeda, H; Takaku, A

    1999-01-01

    We developed a pre-operative simulation and intra-operative navigation system with three-dimensional computer graphics (3D-CG). Because the 3D-CG created by the present system enables visualization of lesions via semitransparent imaging of the scalp surface and brain, the expected operative field could be visualized on the computer display pre-operatively. We used two different configurative navigators. One is assembled by an arciform arm and a laser pointer. The arciform arm consists of 3 joints mounted with rotary encoders forming an iso-center system. The distal end of the arm has a laser pointer, which has a CCD for measurement of the distance between the outlet of the laser beam, and the position illuminated by the laser pointer. Using this navigator, surgeons could accurately estimate the trajectory to the target lesion, and the boundaries of the lesion. Because the other navigator has six degrees of freedom and an interchangeable probe shaped like a bayonet on its tip, it can be used in deep structures through narrow openings. Our system proved efficient and yielded an unobstructed view of deep structures during microscopic neurosurgical procedures.

  2. Parallel computers and three-dimensional computational electromagnetics

    International Nuclear Information System (INIS)

    Madsen, N.K.

    1994-01-01

    The authors have continued to enhance their ability to use new massively parallel processing computers to solve time-domain electromagnetic problems. New vectorization techniques have improved the performance of their code DSI3D by factors of 5 to 15, depending on the computer used. New radiation boundary conditions and far-field transformations now allow the computation of radar cross-section values for complex objects. A new parallel-data extraction code has been developed that allows the extraction of data subsets from large problems, which have been run on parallel computers, for subsequent post-processing on workstations with enhanced graphics capabilities. A new charged-particle-pushing version of DSI3D is under development. Finally, DSI3D has become a focal point for several new Cooperative Research and Development Agreement activities with industrial companies such as Lockheed Advanced Development Company, Varian, Hughes Electron Dynamics Division, General Atomic, and Cray

  3. Accelerating image reconstruction in three-dimensional optoacoustic tomography on graphics processing units.

    Science.gov (United States)

    Wang, Kun; Huang, Chao; Kao, Yu-Jiun; Chou, Cheng-Ying; Oraevsky, Alexander A; Anastasio, Mark A

    2013-02-01

    Optoacoustic tomography (OAT) is inherently a three-dimensional (3D) inverse problem. However, most studies of OAT image reconstruction still employ two-dimensional imaging models. One important reason is because 3D image reconstruction is computationally burdensome. The aim of this work is to accelerate existing image reconstruction algorithms for 3D OAT by use of parallel programming techniques. Parallelization strategies are proposed to accelerate a filtered backprojection (FBP) algorithm and two different pairs of projection/backprojection operations that correspond to two different numerical imaging models. The algorithms are designed to fully exploit the parallel computing power of graphics processing units (GPUs). In order to evaluate the parallelization strategies for the projection/backprojection pairs, an iterative image reconstruction algorithm is implemented. Computer simulation and experimental studies are conducted to investigate the computational efficiency and numerical accuracy of the developed algorithms. The GPU implementations improve the computational efficiency by factors of 1000, 125, and 250 for the FBP algorithm and the two pairs of projection/backprojection operators, respectively. Accurate images are reconstructed by use of the FBP and iterative image reconstruction algorithms from both computer-simulated and experimental data. Parallelization strategies for 3D OAT image reconstruction are proposed for the first time. These GPU-based implementations significantly reduce the computational time for 3D image reconstruction, complementing our earlier work on 3D OAT iterative image reconstruction.

  4. A three-dimensional computational model of collagen network mechanics.

    Directory of Open Access Journals (Sweden)

    Byoungkoo Lee

    Full Text Available Extracellular matrix (ECM strongly influences cellular behaviors, including cell proliferation, adhesion, and particularly migration. In cancer, the rigidity of the stromal collagen environment is thought to control tumor aggressiveness, and collagen alignment has been linked to tumor cell invasion. While the mechanical properties of collagen at both the single fiber scale and the bulk gel scale are quite well studied, how the fiber network responds to local stress or deformation, both structurally and mechanically, is poorly understood. This intermediate scale knowledge is important to understanding cell-ECM interactions and is the focus of this study. We have developed a three-dimensional elastic collagen fiber network model (bead-and-spring model and studied fiber network behaviors for various biophysical conditions: collagen density, crosslinker strength, crosslinker density, and fiber orientation (random vs. prealigned. We found the best-fit crosslinker parameter values using shear simulation tests in a small strain region. Using this calibrated collagen model, we simulated both shear and tensile tests in a large linear strain region for different network geometry conditions. The results suggest that network geometry is a key determinant of the mechanical properties of the fiber network. We further demonstrated how the fiber network structure and mechanics evolves with a local formation, mimicking the effect of pulling by a pseudopod during cell migration. Our computational fiber network model is a step toward a full biomechanical model of cellular behaviors in various ECM conditions.

  5. Computational study of three-dimensional wake structure

    International Nuclear Information System (INIS)

    Himeno, R.; Shirayama, S.; Kamo, K.; Kuwahara, K.

    1986-01-01

    Three-dimensional wake structure is studied by numerically solving the incompressible Navier-Stokes equations. Results are visualized by a three-dimensional color graphic system. It was found that a pair of vortex tubes separated from a body plays the most important role in the wake. Near the body vortex tubes are rather stable, however, they gradually become unsteady as they flow down

  6. Three-dimensional time-lapse velocity tomography of an underground longwall panel

    Energy Technology Data Exchange (ETDEWEB)

    Luxbacher, K.; Westman, E.; Swanson, P.; Karfakis, M. [Virginia Tech., Blacksburg, VA (United States). Dept. of Mining & Minerals Engineering

    2008-06-15

    Three-dimensional velocity tomograms were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts. Mining-induced microseismic events provided passive sources for the three-dimensional velocity tomography. Surface-mounted geophones monitored microseismic activity for 18 days. Eighteen tomograms were generated and high-velocity regions correlated with high abutment stresses predicted by numerical modeling. Additionally, the high-velocity regions were observed to redistribute as the longwall face retreated, indicating that velocity tomography may be an appropriate technology for monitoring stress redistribution in underground mines.

  7. Three-dimensional computer models of electrospinning systems

    Directory of Open Access Journals (Sweden)

    Smółka Krzysztof

    2017-12-01

    Full Text Available Electrospinning is a very interesting method that allows the fabrication of continuous fibers with diameters down to a few nanometers. This paper presents an overview of electrospinning systems as well as their comparison using proposed three-dimensional parameterized numerical models. The presented solutions allow an analysis of the electric field distribution.

  8. Three-dimensional, computer simulated navigation in endoscopic neurosurgery

    Directory of Open Access Journals (Sweden)

    Roberta K. Sefcik, BHA

    2017-06-01

    Conclusion: Three-dimensional, frameless neuronavigation systems are useful in endoscopic neurosurgery to assist in the pre-operative planning of potential trajectories and to help localize the pathology of interest. Neuronavigation appears to be accurate to <1–2 mm without issues related to brain shift. Further work is necessary in the investigation of the effect of neuronavigation on operative time, cost, and patient-centered outcomes.

  9. Three dimensional computation of turbulent flow in meandering channels

    Energy Technology Data Exchange (ETDEWEB)

    Van Thinh Nguyen

    2000-07-01

    In this study a finite element calculation procedure together with two-equation turbulent model k-{epsilon} and mixing length are applied to the problem of simulating 3D turbulent flow in closed and open meandering channels. Near the wall a special approach is applied in order to overcome the weakness of the standard k-{epsilon} in the viscous sub-layer. A specialized shape function is used in the special near wall elements to capture accurately the strong variations of the mean flow variables in the viscosity-affected near wall region. Based on the analogy of water and air flows, a few characteristics of hydraulic problems can be examined in aerodynamic models, respectively. To study the relationships between an aerodynamic and a hydraulic model many experiments have been carried out by Federal Waterway Engineering and Research Institute of Karlsruhe, Germany. In order to test and examine the results of these physical models, an appropriated numerical model is necessary. The numerical mean will capture the limitations of the experimental setup. The similarity and the difference between an aerodynamic and a hydraulic model will be found out by the results of numerical computations and will be depicted in this study. Despite the presence of similarities between the flow in closed channels and the flow in open channels, it should be stated that the presence of a free surface in the open channel introduces serious complications to three dimensional computation. A new unknown, which represents the position of nodes on this free surface, is introduced. A special approach is required for solving this unknown. A procedure surface tracking is applied to the free surface boundary like a moving boundary. Grid nodes on the free surface are free to move in such a way that they belong to the spines, which are the generator lines to define the allowed motion of the nodes on the free surface. (orig.) [German] Die numerische Simulation ist heute ein wichtiges Hilfsmittel fuer die

  10. Three dimensional reconstruction of fossils with X-ray CT and computer graphics

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, Takashi; Tateno, Satoko (Tokyo Univ. (Japan). Coll. of Arts and Sciences); Suzuki, Naoki

    1991-12-01

    We have developed a method for three dimensional (3D) visualization of fossils such as trilobites and ammonites by non-destructive measurement and computer graphics. The imaging techniques in the medical sciences are applied for fossils by us to have quantitative data analyses on the structural and functional features of some extinct creatures. These methods are composed of a high resolutional X-ray computed tomography (X-ray CT) and computer graphics. We are able to observe not only outer shape but also inner structure of fossils as a 3D image by this method. Consequently, the shape and volume are measurable on these 3D image quantitatively. In addition to that, it is able to reconstruct an ideal figure from the deformed fossils by graphical treatments of the data. Such a 3D reconstruction method is useful to obtain a new information from the paleontological standpoint. (author).

  11. Three dimensional reconstruction of fossils with X-ray CT and computer graphics

    International Nuclear Information System (INIS)

    Hamada, Takashi; Tateno, Satoko; Suzuki, Naoki.

    1991-01-01

    We have developed a method for three dimensional (3D) visualization of fossils such as trilobites and ammonites by non-destructive measurement and computer graphics. The imaging techniques in the medical sciences are applied for fossils by us to have quantitative data analyses on the structural and functional features of some extinct creatures. These methods are composed of a high resolutional X-ray computed tomography (X-ray CT) and computer graphics. We are able to observe not only outer shape but also inner structure of fossils as a 3D image by this method. Consequently, the shape and volume are measurable on these 3D image quantitatively. In addition to that, it is able to reconstruct an ideal figure from the deformed fossils by graphical treatments of the data. Such a 3D reconstruction method is useful to obtain a new information from the paleontological standpoint. (author)

  12. Three-dimensional observation of TiO2 nanostructures by electron tomography

    KAUST Repository

    Suh, Young Joon

    2013-03-01

    Three-dimensional nanostructures of TiO2 related materials including nanotubes, electron acceptor materials in hybrid polymer solar cells, and working electrodes of dye sensitized solar cells (DSSCs) were visualized by electron tomography as well as TEM micrographs. The regions on the wall of TiO2 nanotubes where the streptavidins were attached were elucidated by electron tomogram analysis. The coverage of TiO2 nanotubes by streptavidin was also investigated. The TiO2 nanostructures in hybrid polymer solar cells made by sol-gel and atomic layer deposition (ALD) methods and the morphologies of pores between TiO2 particles in DSSCs were also observed by reconstructed three-dimensional images made by electron tomography. © 2012 Elsevier Ltd.

  13. Three-dimensional biomedical imaging

    International Nuclear Information System (INIS)

    Robb, R.A.

    1985-01-01

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

  14. Three-dimensional structural analysis of eukaryotic flagella/cilia by electron cryo-tomography

    International Nuclear Information System (INIS)

    Bui, Khanh Huy; Pigino, Gaia; Ishikawa, Takashi

    2011-01-01

    Based on the molecular architecture revealed by electron cryo-tomography, the mechanism of the bending motion of eukaryotic flagella/cilia is discussed. Electron cryo-tomography is a potential approach to analyzing the three-dimensional conformation of frozen hydrated biological macromolecules using electron microscopy. Since projections of each individual object illuminated from different orientations are merged, electron tomography is capable of structural analysis of such heterogeneous environments as in vivo or with polymorphism, although radiation damage and the missing wedge are severe problems. Here, recent results on the structure of eukaryotic flagella, which is an ATP-driven bending organelle, from green algae Chlamydomonas are presented. Tomographic analysis reveals asymmetric molecular arrangements, especially that of the dynein motor proteins, in flagella, giving insight into the mechanism of planar asymmetric bending motion. Methodological challenges to obtaining higher-resolution structures from this technique are also discussed

  15. Three dimensional image reconstruction of computed tomograms of the head and neck in the pediatric age group

    International Nuclear Information System (INIS)

    Armstrong, E.A.; Smith, T.H.; Salyer, K.E.

    1985-01-01

    Between August 1983, and April 1984, we have clinically evaluated an experimental computed tomography (CT) software package capable of producing three dimensional (3-D) reconstructed images from axial CT scans. Three dimensional reconstructions have been performed in 115 patient CT examinations for congenital or acquired craniofacial abnormalities, 103 patients; intracranial neoplasms, 6 patients: and the cervical spine and craniocervical junction, 6 patients. Several patients have had studies pre- and postoperatively to plan craniofacial surgery and later evaluate its results on both the bone and soft tissue structures. The results indicate that three dimensional reconstruction using a low dose technique yields information valuable to conceptualize and demonstrate to clinicians the spatial relationships of often complex anatomical relationships in the craniofacial and craniocervical areas [fr

  16. Three-Dimensional Computer Visualization of Forensic Pathology Data

    OpenAIRE

    March, Jack; Schofield, Damian; Evison, Martin; Woodford, Noel

    2004-01-01

    Despite a decade of use in US courtrooms, it is only recently that forensic computer animations have become an increasingly important form of communication in legal spheres within the United Kingdom. Aims Research at the University of Nottingham has been influential in the critical investigation of forensic computer graphics reconstruction methodologies and techniques and in raising the profile of this novel form of data visualization within the United Kingdom. The case study presented demons...

  17. Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Badia-Martinez, Daniel; Peralta, Bibiana [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Andres, German; Guerra, Milagros [Electron Microscopy Unit, Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Campus Cantoblanco, 28049 Madrid (Spain); Gil-Carton, David [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Abrescia, Nicola G.A., E-mail: nabrescia@cicbiogune.es [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

    2012-09-01

    Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.

  18. Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography

    International Nuclear Information System (INIS)

    Badia-Martinez, Daniel; Peralta, Bibiana; Andrés, German; Guerra, Milagros; Gil-Carton, David; Abrescia, Nicola G.A.

    2012-01-01

    Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.

  19. Three-dimensional ophthalmic optical coherence tomography with a refraction correction algorithm

    Science.gov (United States)

    Zawadzki, Robert J.; Leisser, Christoph; Leitgeb, Rainer; Pircher, Michael; Fercher, Adolf F.

    2003-10-01

    We built an optical coherence tomography (OCT) system with a rapid scanning optical delay (RSOD) line, which allows probing full axial eye length. The system produces Three-dimensional (3D) data sets that are used to generate 3D tomograms of the model eye. The raw tomographic data were processed by an algorithm, which is based on Snell"s law to correct the interface positions. The Zernike polynomials representation of the interfaces allows quantitative wave aberration measurements. 3D images of our results are presented to illustrate the capabilities of the system and the algorithm performance. The system allows us to measure intra-ocular distances.

  20. Three-dimensional computer visualization of forensic pathology data.

    Science.gov (United States)

    March, Jack; Schofield, Damian; Evison, Martin; Woodford, Noel

    2004-03-01

    Despite a decade of use in US courtrooms, it is only recently that forensic computer animations have become an increasingly important form of communication in legal spheres within the United Kingdom. Aims Research at the University of Nottingham has been influential in the critical investigation of forensic computer graphics reconstruction methodologies and techniques and in raising the profile of this novel form of data visualization within the United Kingdom. The case study presented demonstrates research undertaken by Aims Research and the Department of Forensic Pathology at the University of Sheffield, which aims to apply, evaluate, and develop novel 3-dimensional computer graphics (CG) visualization and virtual reality (VR) techniques in the presentation and investigation of forensic information concerning the human body. The inclusion of such visualizations within other CG or VR environments may ultimately provide the potential for alternative exploratory directions, processes, and results within forensic pathology investigations.

  1. Single-Frame Cinema. Three Dimensional Computer-Generated Imaging.

    Science.gov (United States)

    Cheetham, Edward Joseph, II

    This master's thesis provides a description of the proposed art form called single-frame cinema, which is a category of computer imagery that takes the temporal polarities of photography and cinema and unites them into a single visual vignette of time. Following introductory comments, individual chapters discuss (1) the essential physical…

  2. Three-dimensional analysis of cellular microstructures by computer simulation

    International Nuclear Information System (INIS)

    Hanson, K.; Morris, J.W. Jr.

    1977-06-01

    For microstructures of the ''cellular'' type (isotropic growth from a distribution of nuclei which form simultaneously), it is possible to construct an efficient code which will completely analyze the microstructure in three dimensions. Such a computer code for creating and storing the connected graph was constructed

  3. [Application of three-dimensional computer graphics in oncology].

    Science.gov (United States)

    Joyeux, H; Jaeger, M; Briand, D; Servois, V; Masson, B; Borianne, P; de Reffye, P

    1996-01-01

    Accurate 3D tumoral volume evaluation is now possible through the combined use and progress of computer graphics technics (3D reconstruction and visualization) and medical imagery (helicoidal TDM scanner). Specific organ and pathology oriented softwares can help answer rapidly to problems posed by oncologic praticians. A new decision support for diagnosis, therapy and follow-up is emerging. First results in liver tumors and hepatic regeneration macroscopic biometrics are presented. Tumoral or organ volumic index will be usable in the follow-up. TNM staging, external conformal radiotherapy for prostatic or brain tumors, drugs cytolytic effects evaluation will take great advantage of these technologies. 3D visualization and matching CT and MRI imagery can help computed assisted surgery.

  4. Three-dimensional in vivo fluorescence diffuse optical tomography of breast cancer in humans

    Science.gov (United States)

    Corlu, Alper; Choe, Regine; Durduran, Turgut; Rosen, Mark A.; Schweiger, Martin; Arridge, Simon R.; Schnall, Mitchell D.; Yodh, Arjun G.

    2007-05-01

    We present three-dimensional (3D) in vivo images of human breast cancer based on fluorescence diffuse optical tomography (FDOT). To our knowledge, this work represents the first reported 3D fluorescence tomography of human breast cancer in vivo. In our protocol, the fluorophore Indocyanine Green (ICG) is injected intravenously. Fluorescence excitation and detection are accomplished in the soft-compression, parallel-plane, transmission geometry using laser sources at 786 nm and spectrally filtered CCD detection. Phantom and in vivo studies confirm the signals are due to ICG fluorescence, rather than tissue autofluorescence and excitation light leakage. Fluorescence images of breast tumors were in good agreement with those of MRI, and with DOT based on endogenous contrast. Tumorto- normal tissue contrast based on ICG fluorescence was two-to-four-fold higher than contrast based on hemoglobin and scattering parameters. In total the measurements demonstrate that FDOT of breast cancer is feasible and promising.

  5. THREE-DIMENSIONAL DOPPLER TOMOGRAPHY OF THE RS VULPECULAE INTERACTING BINARY

    International Nuclear Information System (INIS)

    Richards, Mercedes T.; Sharova, Olga I.; Agafonov, Michail I.

    2010-01-01

    Three-dimensional Doppler tomography has been used to study the Hα emission sources in the RS Vulpeculae (RS Vul) interacting binary. The two-dimensional tomogram of this binary suggested that most of the emission arises from the cool mass losing star with additional evidence of a gas stream flowing close to its predicted trajectory. However, the three-dimensional tomogram revealed surprising evidence that the gas stream has an average velocity of -85 km s -1 relative to the central velocity plane at V z = 0 km s -1 , unlike U CrB in which the stream was prominent along this central plane. These unexpected V z motions may result from the interaction between magnetic activity on the cool star and the gravitationally induced Roche lobe overflow from that star. Evidence of a loop prominence on the cool star close to the L1 point has been found in the three-dimensional tomogram of RS Vul; hence, the magnetic field lines may have deflected the gas stream relative to the central plane. This result is consistent with earlier detections of RS Vul as both an X-ray and a radio source, and represents the first detection of a loop prominence in an interacting binary based on tomography. Moreover, recent radio images of β Per, the prototype of the Algols, show that the magnetic field of the mass losing star is asymmetric and extends well beyond the orbital plane of the binary, so it is now plausible that the gas flow between the stars in RS Vul could be deflected in an asymmetric way by the magnetic field.

  6. A three-dimensional computer graphic imaging for neurosurgery

    International Nuclear Information System (INIS)

    Uchino, Masafumi; Onagi, Atsuo; Seiki, Yoshikatsu

    1987-01-01

    Information offered by conventional diagnostic tools for medical use, including X-ray films, CT, MRI, RI images and PET, are usually two-dimensional. However, the human body and pathological lesions are really extended in 3 dimensions. Interpreters have to reconstruct an imaginative, 3-dimensional configuration of lesions from 2-dimensional information on many films, according to their knowledge and experience. All this sometimes wastes a lot of time and gives rise to inconclusive discussion among interpreters. The advent and rapid progress of new computer graphic techniques, however, makes it possible to draw an apparent 3-dimensional image of a lesion on the basis of a 2-dimensional display; this is named a pseudo-3-dimensional image. After the region of interest of the CT-sliced image has been extracted by means of a semi-automatic contour extraction algorithm, multi-slice CT images are constructed by the voxel method. A 3-dimensional image is then generated by the use of the Z-buffer. Subsequently, transparent, semi-transparent, and color display are provided. This new method of display was used for CT-scan films of various intracerebral pathological lesions, including tumors, hematomas, and congenital anomalies: The benefits, prospects, and technical limits of this imaging technique for clinical use were discussed. (author)

  7. Three Dimensional Computer Graphics Federates for the 2012 Smackdown Simulation

    Science.gov (United States)

    Fordyce, Crystal; Govindaiah, Swetha; Muratet, Sean; O'Neil, Daniel A.; Schricker, Bradley C.

    2012-01-01

    The Simulation Interoperability Standards Organization (SISO) Smackdown is a two-year old annual event held at the 2012 Spring Simulation Interoperability Workshop (SIW). A primary objective of the Smackdown event is to provide college students with hands-on experience in developing distributed simulations using High Level Architecture (HLA). Participating for the second time, the University of Alabama in Huntsville (UAHuntsville) deployed four federates, two federates simulated a communications server and a lunar communications satellite with a radio. The other two federates generated 3D computer graphics displays for the communication satellite constellation and for the surface based lunar resupply mission. Using the Light-Weight Java Graphics Library, the satellite display federate presented a lunar-texture mapped sphere of the moon and four Telemetry Data Relay Satellites (TDRS), which received object attributes from the lunar communications satellite federate to drive their motion. The surface mission display federate was an enhanced version of the federate developed by ForwardSim, Inc. for the 2011 Smackdown simulation. Enhancements included a dead-reckoning algorithm and a visual indication of which communication satellite was in line of sight of Hadley Rille. This paper concentrates on these two federates by describing the functions, algorithms, HLA object attributes received from other federates, development experiences and recommendations for future, participating Smackdown teams.

  8. Three dimensional reconstruction of computed tomographic images by computer graphics method

    International Nuclear Information System (INIS)

    Kashiwagi, Toru; Kimura, Kazufumi.

    1986-01-01

    A three dimensional computer reconstruction system for CT images has been developed in a commonly used radionuclide data processing system using a computer graphics technique. The three dimensional model was constructed from organ surface information of CT images (slice thickness: 5 or 10 mm). Surface contours of the organs were extracted manually from a set of parallel transverse CT slices in serial order and stored in the computer memory. Interpolation was made between a set of the extracted contours by cubic spline functions, then three dimensional models were reconstructed. The three dimensional images were displayed as a wire-frame and/or solid models on the color CRT. Solid model images were obtained as follows. The organ surface constructed from contours was divided into many triangular patches. The intensity of light to each patch was calculated from the direction of incident light, eye position and the normal to the triangular patch. Firstly, this system was applied to the liver phantom. Reconstructed images of the liver phantom were coincident with the actual object. This system also has been applied to human various organs such as brain, lung, liver, etc. The anatomical organ surface was realistically viewed from any direction. The images made us more easily understand the location and configuration of organs in vivo than original CT images. Furthermore, spacial relationship among organs and/or lesions was clearly obtained by superimposition of wire-frame and/or different colored solid models. Therefore, it is expected that this system is clinically useful for evaluating the patho-morphological changes in broad perspective. (author)

  9. Three dimensional analysis of coelacanth body structure by computer graphics and X-ray CT images

    International Nuclear Information System (INIS)

    Suzuki, Naoki; Hamada, Takashi.

    1990-01-01

    Three dimensional imaging processes were applied for the structural and functional analyses of the modern coelacanth (Latimeria chalumnae). Visualization of the obtained images is performed with computer graphics on the basis of serial images by an X-ray CT scanning method. Reconstruction of three dimensional images of the body structure of coelacanth using the volume rendering and surface rendering methods provides us various information about external and internal shapes of this exquisite fish. (author)

  10. Three-Dimensional Cataract Crystalline Lens Imaging With Swept-Source Optical Coherence Tomography.

    Science.gov (United States)

    de Castro, Alberto; Benito, Antonio; Manzanera, Silvestre; Mompeán, Juan; Cañizares, Belén; Martínez, David; Marín, Jose María; Grulkowski, Ireneusz; Artal, Pablo

    2018-02-01

    To image, describe, and characterize different features visible in the crystalline lens of older adults with and without cataract when imaged three-dimensionally with a swept-source optical coherence tomography (SS-OCT) system. We used a new SS-OCT laboratory prototype designed to enhance the visualization of the crystalline lens and imaged the entire anterior segment of both eyes in two groups of participants: patients scheduled to undergo cataract surgery, n = 17, age range 36 to 91 years old, and volunteers without visual complains, n = 14, age range 20 to 81 years old. Pre-cataract surgery patients were also clinically graded according to the Lens Opacification Classification System III. The three-dimensional location and shape of the visible opacities were compared with the clinical grading. Hypo- and hyperreflective features were visible in the lens of all pre-cataract surgery patients and in some of the older adults in the volunteer group. When the clinical examination revealed cortical or subcapsular cataracts, hyperreflective features were visible either in the cortex parallel to the surfaces of the lens or in the posterior pole. Other type of opacities that appeared as hyporeflective localized features were identified in the cortex of the lens. The OCT signal in the nucleus of the crystalline lens correlated with the nuclear cataract clinical grade. A dedicated OCT is a useful tool to study in vivo the subtle opacities in the cataractous crystalline lens, revealing its position and size three-dimensionally. The use of these images allows obtaining more detailed information on the age-related changes leading to cataract.

  11. Three dimensional imaging of damage in structural materials using high resolution micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Buffiere, J.-Y. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France)]. E-mail: jean-yves.buffiere@insa-lyon.fr; Proudhon, H. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Ferrie, E. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Ludwig, W. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Maire, E. [GEMPPM UMR CNRS 5510, INSA Lyon, 20 Av. A. Einstein, 69621 Villeurbanne Cedex (France); Cloetens, P. [ESRF Grenoble (France)

    2005-08-15

    This paper presents recent results showing the ability of high resolution synchrotron X-ray micro-tomography to image damage initiation and development during mechanical loading of structural metallic materials. First, the initiation, growth and coalescence of porosities in the bulk of two metal matrix composites have been imaged at different stages of a tensile test. Quantitative data on damage development has been obtained and related to the nature of the composite matrix. Second, three dimensional images of fatigue crack have been obtained in situ for two different Al alloys submitted to fretting and/or uniaxial in situ fatigue. The analysis of those images shows the strong interaction of the cracks with the local microstructure and provides unique experimental data for modelling the behaviour of such short cracks.

  12. Three dimensional imaging of damage in structural materials using high resolution micro-tomography

    International Nuclear Information System (INIS)

    Buffiere, J.-Y.; Proudhon, H.; Ferrie, E.; Ludwig, W.; Maire, E.; Cloetens, P.

    2005-01-01

    This paper presents recent results showing the ability of high resolution synchrotron X-ray micro-tomography to image damage initiation and development during mechanical loading of structural metallic materials. First, the initiation, growth and coalescence of porosities in the bulk of two metal matrix composites have been imaged at different stages of a tensile test. Quantitative data on damage development has been obtained and related to the nature of the composite matrix. Second, three dimensional images of fatigue crack have been obtained in situ for two different Al alloys submitted to fretting and/or uniaxial in situ fatigue. The analysis of those images shows the strong interaction of the cracks with the local microstructure and provides unique experimental data for modelling the behaviour of such short cracks

  13. Three Dimensional Visualization for the Steam Injection into Water Pool using Electrical Resistance Tomography

    International Nuclear Information System (INIS)

    Khambampati, Anil Kumar; Lee, Jeong Seong; Kim, Sin; Kim, Kyung Youn

    2010-01-01

    The direct injection of steam into a water pool is a method of heat transfer used in many process industries. The amount of research in this area however is limited to the nuclear industry, with applications relating to reactor cooling systems. Electrical resistance tomography (ERT), a low cost, non-invasive and which has high temporal resolution characteristics, can be used as a visualization tool for the resistivity distribution for the steam injection into water pool such as IRWST. In this paper, three dimensional resistivity distribution of the process is obtained through ERT using iterative Gauss-Newton method. Numerical experiments are performed by assuming different resistive objects in the water pool. Numerical results show that ERT is successful in estimating the resistivity distribution for the injection of steam in the water pool

  14. Three-dimensional ground penetrating radar imaging using multi-frequency diffraction tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mast, J.E.; Johansson, E.M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    In this talk we present results from a three-dimensional image reconstruction algorithm for impulse radar operating in monostatic pule-echo mode. The application of interest to us is the nondestructive evaluation of civil structures such as bridge decks. We use a multi-frequency diffraction tomography imaging technique in which coherent backward propagations of the received reflected wavefield form a spatial image of the scattering interfaces within the region of interest. This imaging technique provides high-resolution range and azimuthal visualization of the subsurface region. We incorporate the ability to image in planarly layered conductive media and apply the algorithm to experimental data from an offset radar system in which the radar antenna is not directly coupled to the surface of the region. We present a rendering in three-dimensions of the resulting image data which provides high-detail visualization.

  15. Three-dimensional architecture of hair-cell linkages as revealedby electron-microscopic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Auer, Manfred; Koster, Bram; Ziese, Ulrike; Bajaj, Chandrajit; Volkmann, Niels; Wang, Da Neng; Hudspeth, A. James

    2006-07-28

    The senses of hearing and balance rest upon mechanoelectrical transduction by the hair bundles of hair cells in the inner ear. Located at the apical cellular surface, each hair bundle comprises several tens of stereocilia and a single kinocilium that are interconnected by extracellular proteinaceous links. Using electron-microscopic tomography of bullfrog saccular sensory epithelia, we examined the three-dimensional structures of ankle or basal links, kinociliary links, and tip links. We observed clear differences in the dimensions and appearances of the three links. We found two distinct populations of tip links suggestive of the involvement of two proteins or splice variants. We noted auxiliary links connecting the upper portions of tip links to the taller stereocilia. Tip links and auxiliary links show a tendency to adopt a globular conformation when disconnected from the membrane surface.

  16. Three-dimensional rendering of otolith growth using phase contrast synchrotron tomography.

    Science.gov (United States)

    Mapp, J J I; Fisher, M H; Atwood, R C; Bell, G D; Greco, M K; Songer, S; Hunter, E

    2016-05-01

    A three-dimensional computer reconstruction of a plaice Pleuronectes platessa otolith is presented from data acquired by the Diamond Light synchrotron, beamline I12, X-ray source, a high energy (53-150 keV) source particularly well suited to the study of dense objects. The data allowed non-destructive rendering of otolith structure, and for the first time allows otolith annuli (internal ring structures) to be analysed in X-ray tomographic images. © 2016 The Fisheries Society of the British Isles.

  17. Three-dimensional computed tomographic volumetry precisely predicts the postoperative pulmonary function.

    Science.gov (United States)

    Kobayashi, Keisuke; Saeki, Yusuke; Kitazawa, Shinsuke; Kobayashi, Naohiro; Kikuchi, Shinji; Goto, Yukinobu; Sakai, Mitsuaki; Sato, Yukio

    2017-11-01

    It is important to accurately predict the patient's postoperative pulmonary function. The aim of this study was to compare the accuracy of predictions of the postoperative residual pulmonary function obtained with three-dimensional computed tomographic (3D-CT) volumetry with that of predictions obtained with the conventional segment-counting method. Fifty-three patients scheduled to undergo lung cancer resection, pulmonary function tests, and computed tomography were enrolled in this study. The postoperative residual pulmonary function was predicted based on the segment-counting and 3D-CT volumetry methods. The predicted postoperative values were compared with the results of postoperative pulmonary function tests. Regarding the linear correlation coefficients between the predicted postoperative values and the measured values, those obtained using the 3D-CT volumetry method tended to be higher than those acquired using the segment-counting method. In addition, the variations between the predicted and measured values were smaller with the 3D-CT volumetry method than with the segment-counting method. These results were more obvious in COPD patients than in non-COPD patients. Our findings suggested that the 3D-CT volumetry was able to predict the residual pulmonary function more accurately than the segment-counting method, especially in patients with COPD. This method might lead to the selection of appropriate candidates for surgery among patients with a marginal pulmonary function.

  18. Assessment of three-dimensional setup errors in image-guided pelvic radiotherapy for uterine and cervical cancer using kilovoltage cone-beam computed tomography and its effect on planning target volume margins.

    Science.gov (United States)

    Patni, Nidhi; Burela, Nagarjuna; Pasricha, Rajesh; Goyal, Jaishree; Soni, Tej Prakash; Kumar, T Senthil; Natarajan, T

    2017-01-01

    To achieve the best possible therapeutic ratio using high-precision techniques (image-guided radiation therapy/volumetric modulated arc therapy [IGRT/VMAT]) of external beam radiation therapy in cases of carcinoma cervix using kilovoltage cone-beam computed tomography (kV-CBCT). One hundred and five patients of gynecological malignancies who were treated with IGRT (IGRT/VMAT) were included in the study. CBCT was done once a week for intensity-modulated radiation therapy and daily in IGRT/VMAT. These images were registered with the planning CT scan images and translational errors were applied and recorded. In all, 2078 CBCT images were studied. The margins of planning target volume were calculated from the variations in the setup. The setup variation was 5.8, 10.3, and 5.6 mm in anteroposterior, superoinferior, and mediolateral direction. This allowed adequate dose delivery to the clinical target volume and the sparing of organ at risks. Daily kV-CBCT is a satisfactory method of accurate patient positioning in treating gynecological cancers with high-precision techniques. This resulted in avoiding geographic miss.

  19. Three-dimensional reciprocal space x-ray coherent scattering tomography of two-dimensional object.

    Science.gov (United States)

    Zhu, Zheyuan; Pang, Shuo

    2018-04-01

    X-ray coherent scattering tomography is a powerful tool in discriminating biological tissues and bio-compatible materials. Conventional x-ray scattering tomography framework can only resolve isotropic scattering profile under the assumption that the material is amorphous or in powder form, which is not true especially for biological samples with orientation-dependent structure. Previous tomography schemes based on x-ray coherent scattering failed to preserve the scattering pattern from samples with preferred orientations, or required elaborated data acquisition scheme, which could limit its application in practical settings. Here, we demonstrate a simple imaging modality to preserve the anisotropic scattering signal in three-dimensional reciprocal (momentum transfer) space of a two-dimensional sample layer. By incorporating detector movement along the direction of x-ray beam, combined with a tomographic data acquisition scheme, we match the five dimensions of the measurements with the five dimensions (three in momentum transfer domain, and two in spatial domain) of the object. We employed a collimated pencil beam of a table-top copper-anode x-ray tube, along with a panel detector to investigate the feasibility of our method. We have demonstrated x-ray coherent scattering tomographic imaging at a spatial resolution ~2 mm and momentum transfer resolution 0.01 Å -1 for the rotation-invariant scattering direction. For any arbitrary, non-rotation-invariant direction, the same spatial and momentum transfer resolution can be achieved based on the spatial information from the rotation-invariant direction. The reconstructed scattering profile of each pixel from the experiment is consistent with the x-ray diffraction profile of each material. The three-dimensional scattering pattern recovered from the measurement reveals the partially ordered molecular structure of Teflon wrap in our sample. We extend the applicability of conventional x-ray coherent scattering tomography to

  20. Three-Dimensional Computer-Assisted Two-Layer Elastic Models of the Face.

    Science.gov (United States)

    Ueda, Koichi; Shigemura, Yuka; Otsuki, Yuki; Fuse, Asuka; Mitsuno, Daisuke

    2017-11-01

    To make three-dimensional computer-assisted elastic models for the face, we decided on five requirements: (1) an elastic texture like skin and subcutaneous tissue; (2) the ability to take pen marking for incisions; (3) the ability to be cut with a surgical knife; (4) the ability to keep stitches in place for a long time; and (5) a layered structure. After testing many elastic solvents, we have made realistic three-dimensional computer-assisted two-layer elastic models of the face and cleft lip from the computed tomographic and magnetic resonance imaging stereolithographic data. The surface layer is made of polyurethane and the inner layer is silicone. Using this elastic model, we taught residents and young doctors how to make several typical local flaps and to perform cheiloplasty. They could experience realistic simulated surgery and understand three-dimensional movement of the flaps.

  1. An evaluation of clinical, radiological and three-dimensional dental tomography findings in ectodermal dysplasia cases.

    Science.gov (United States)

    Doğan, Mehmet-Sinan; Callea, Michele; Yavuz, Ìzzet; Aksoy, Orhan; Clarich, Gabriella; Günay, Ayse; Günay, Ahmet; Güven, Sedat; Maglione, Michele; Akkuş, Zeki

    2015-05-01

    This study aimed to review the results related to head and jaw disorders in cases of ectodermal dysplasia. The evaluation of ectodermal dysplasia cases was made by clinical examination and examination of the jaw and facial areas radiologically and on cone-beam 3-dimensional dental tomography (CBCT) images. In the 36 cases evaluated in the study, typical clinical findings of pure hypohidrotic ectodermal displasia (HED) were seen, such as missing teeth, dry skin, hair and nail disorders. CBCT images were obtained from 12 of the 36 cases, aged 1.5- 45 years, and orthodontic analyses were made on these images. The clinical and radiological evaluations determined, hypodontia or oligodontia, breathing problems, sweating problems, a history of fever, sparse hair, saddle nose, skin peeling, hypopigmentation, hyperpigmentation, finger and nail deformities, conical teeth anomalies, abnormal tooth root formation, tooth resorption in the root, gingivitis, history of epilepsy, absent lachrymal canals and vision problems in the cases which included to the study. Ectodermal dysplasia cases have a particular place in dentistry and require a professional, multi-disciplinary approach in respect of the chewing function, orthognathic problems, growth, oral and dental health. It has been understood that with data obtained from modern technologies such as three-dimensional dental tomography and the treatments applied, the quality of life of these cases can be improved.

  2. Three-dimensional imaging of artificial fingerprint by optical coherence tomography

    Science.gov (United States)

    Larin, Kirill V.; Cheng, Yezeng

    2008-03-01

    Fingerprint recognition is one of the popular used methods of biometrics. However, due to the surface topography limitation, fingerprint recognition scanners are easily been spoofed, e.g. using artificial fingerprint dummies. Thus, biometric fingerprint identification devices need to be more accurate and secure to deal with different fraudulent methods including dummy fingerprints. Previously, we demonstrated that Optical Coherence Tomography (OCT) images revealed the presence of the artificial fingerprints (made from different household materials, such as cement and liquid silicone rubber) at all times, while the artificial fingerprints easily spoofed the commercial fingerprint reader. Also we demonstrated that an analysis of the autocorrelation of the OCT images could be used in automatic recognition systems. Here, we exploited the three-dimensional (3D) imaging of the artificial fingerprint by OCT to generate vivid 3D image for both the artificial fingerprint layer and the real fingerprint layer beneath. With the reconstructed 3D image, it could not only point out whether there exists an artificial material, which is intended to spoof the scanner, above the real finger, but also could provide the hacker's fingerprint. The results of these studies suggested that Optical Coherence Tomography could be a powerful real-time noninvasive method for accurate identification of artificial fingerprints real fingerprints as well.

  3. A computer program for fitting smooth surfaces to an aircraft configuration and other three dimensional geometries

    Science.gov (United States)

    Craidon, C. B.

    1975-01-01

    A computer program that uses a three-dimensional geometric technique for fitting a smooth surface to the component parts of an aircraft configuration is presented. The resulting surface equations are useful in performing various kinds of calculations in which a three-dimensional mathematical description is necessary. Programs options may be used to compute information for three-view and orthographic projections of the configuration as well as cross-section plots at any orientation through the configuration. The aircraft geometry input section of the program may be easily replaced with a surface point description in a different form so that the program could be of use for any three-dimensional surface equations.

  4. Computational hemodynamics of an implanted coronary stent based on three-dimensional cine angiography reconstruction.

    Science.gov (United States)

    Chen, Mounter C Y; Lu, Po-Chien; Chen, James S Y; Hwang, Ned H C

    2005-01-01

    Coronary stents are supportive wire meshes that keep narrow coronary arteries patent, reducing the risk of restenosis. Despite the common use of coronary stents, approximately 20-35% of them fail due to restenosis. Flow phenomena adjacent to the stent may contribute to restenosis. Three-dimensional computational fluid dynamics (CFD) and reconstruction based on biplane cine angiography were used to assess coronary geometry and volumetric blood flows. A patient-specific left anterior descending (LAD) artery was reconstructed from single-plane x-ray imaging. With corresponding electrocardiographic signals, images from the same time phase were selected from the angiograms for dynamic three-dimensional reconstruction. The resultant three-dimensional LAD artery at end-diastole was adopted for detailed analysis. Both the geometries and flow fields, based on a computational model from CAE software (ANSYS and CATIA) and full three-dimensional Navier-Stroke equations in the CFD-ACE+ software, respectively, changed dramatically after stent placement. Flow fields showed a complex three-dimensional spiral motion due to arterial tortuosity. The corresponding wall shear stresses, pressure gradient, and flow field all varied significantly after stent placement. Combined angiography and CFD techniques allow more detailed investigation of flow patterns in various segments. The implanted stent(s) may be quantitatively studied from the proposed hemodynamic modeling approach.

  5. Preoperative assessment of pleural adhesion by Four-Dimensional Ultra-Low-Dose Computed Tomography (4D-ULDCT) with Adaptive Iterative Dose Reduction using Three-Dimensional processing (AIDR-3D).

    Science.gov (United States)

    Hashimoto, Masayuki; Nagatani, Yukihiro; Oshio, Yasuhiko; Nitta, Norihisa; Yamashiro, Tsuneo; Tsukagoshi, Shinsuke; Ushio, Noritoshi; Mayumi, Masayuki; Kimoto, Tatsuya; Igarashi, Tomoyuki; Yoshigoe, Makoto; Iwai, Kyohei; Tanaka, Koki; Sato, Shigetaka; Sonoda, Akinaga; Otani, Hideji; Murata, Kiyoshi; Hanaoka, Jun

    2018-01-01

    To assess the feasibility of Four-Dimensional Ultra-Low-Dose Computed Tomography (4D-ULDCT) for distinguishing pleural aspects with localized pleural adhesion (LPA) from those without. Twenty-seven patients underwent 4D-ULDCT during a single respiration with a 16cm-coverage of the body axis. The presence and severity of LPA was confirmed by their intraoperative thoracoscopic findings. A point on the pleura and a corresponding point on the outer edge of the costal bone were placed in identical axial planes at end-inspiration. The distance of the two points (PCD), traced by automatic tracking functions respectively, was calculated at each respiratory phase. The maximal and average change amounts in PCD (PCD MCA and PCD ACA ) were compared among 110 measurement points (MPs) without LPA, 16MPs with mild LPA and 10MPs with severe LPA in upper lung field cranial to the bronchial bifurcation (ULF), and 150MPs without LPA, 17MPs with mild LPA and 9MPs with severe LPA in lower lung field caudal to the bronchial bifurcation (LLF) using the Mann-Whitney U test. In the LLF, PCD ACA as well as PCD MCA demonstrated a significant difference among non-LPA, mild LPA and severe LPA (18.1±9.2, 12.3±6.2 and 5.0±3.3mm) (p<0.05). Also in the ULF, PCD ACA showed a significant difference among three conditions (9.2±5.5, 5.7±2.8 and 2.2±0.4mm, respectively) (p<0.05), whereas PCD MCA for mild LPA was similar to that for non-LPA (12.3±5.9 and 17.5±11.0mm). Four D-ULDCT could be a useful non-invasive preoperative assessment modality for the detection of the presence or severity of LPA. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. STAB: A kinetic, three-dimensional, one-group digital computer program

    International Nuclear Information System (INIS)

    Curtis, A.R.; Tyror, J.G.; Wrigley, H.E.

    1961-10-01

    A computer program for solving the one-group, time dependent, three-dimensional diffusion equation together with auxiliary equations representing heat transfer, xenon production and control rod movements, is presented. The equations and the methods of solution are discussed. (author)

  7. Development of a technique for three-dimensional image reconstruction from emission computed tomograms (ECT)

    International Nuclear Information System (INIS)

    Gerischer, R.

    1987-01-01

    The described technique for three-dimensional image reconstruction from ECT sections is based on a simple procedure, which can be carried out with the aid of any standard-type computer used in nuclear medicine and requires no sophisticated arithmetic approach. (TRV) [de

  8. Angular interpolations and splice options for three-dimensional transport computations

    International Nuclear Information System (INIS)

    Abu-Shumays, I.K.; Yehnert, C.E.

    1996-01-01

    New, accurate and mathematically rigorous angular Interpolation strategies are presented. These strategies preserve flow and directionality separately over each octant of the unit sphere, and are based on a combination of spherical harmonics expansions and least squares algorithms. Details of a three-dimensional to three-dimensional (3-D to 3-D) splice method which utilizes the new angular interpolations are summarized. The method has been implemented in a multidimensional discrete ordinates transport computer program. Various features of the splice option are illustrated by several applications to a benchmark Dog-Legged Void Neutron (DLVN) streaming and transport experimental assembly

  9. Three-dimensional magnetic field computation on a distributed memory parallel processor

    International Nuclear Information System (INIS)

    Barion, M.L.

    1990-01-01

    The analysis of three-dimensional magnetic fields by finite element methods frequently proves too onerous a task for the computing resource on which it is attempted. When non-linear and transient effects are included, it may become impossible to calculate the field distribution to sufficient resolution. One approach to this problem is to exploit the natural parallelism in the finite element method via parallel processing. This paper reports on an implementation of a finite element code for non-linear three-dimensional low-frequency magnetic field calculation on Intel's iPSC/2

  10. Influence of knee flexion angle and transverse drill angle on creation of femoral tunnels in double-bundle anterior cruciate ligament reconstruction using the transportal technique: Three-dimensional computed tomography simulation analysis.

    Science.gov (United States)

    Choi, Chong Hyuk; Kim, Sung-Jae; Chun, Yong-Min; Kim, Sung-Hwan; Lee, Su-Keon; Eom, Nam-Kyu; Jung, Min

    2018-01-01

    The purpose of this study was to find appropriate flexion angle and transverse drill angle for optimal femoral tunnels of anteromedial (AM) bundle and posterolateral (PL) bundle in double-bundle ACL reconstruction using transportal technique. Thirty three-dimensional knee models were reconstructed. Knee flexion angles were altered from 100° to 130° at intervals of 10°. Maximum transverse drill angle (MTA), MTA minus 10° and 20° were set up. Twelve different tunnels were determined by four flexion angles and three transverse drill angles for each bundle. Tunnel length, wall breakage, inter-tunnel communication and graft-bending angle were assessed. Mean tunnel length of AM bundle was >30mm at 120° and 130° of flexion in all transverse drill angles. Mean tunnel length of PL bundle was >30mm during every condition. There were ≥1 cases of wall breakage except at 120° and 130° of flexion with MTA for AM bundle. There was no case of wall breakage for PL bundle. Considering inter-tunnel gap of >2mm without communication and obtuse graft-bending angle, 120° of flexion and MTA could be recommended as optimal condition for femoral tunnels of AM and PL bundles. Flexion angle and transverse drill angle had combined effect on femoral tunnel in double-bundle ACL reconstruction using transportal technique. Achieving flexion angle of 120° and transverse drill angle close to the medial femoral condyle could be recommended as optimal condition for femoral tunnels of AM and PL bundles to avoid insufficient tunnel length, wall breakage, inter-tunnel communication and acute graft-bending angle. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Reporducibilities of cephalometric measurements of three-dimensional CT images reconstructed in the personal computer

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Kug Jin; Park, Hyok; Lee, Hee Cheol; Kim, Kee Deog; Park, Chang Seo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2003-09-15

    The purpose of this study was to report the reproducibility of intra-observer and inter-observer consistency of cephalometric measurements using three-dimensional (3D) computed tomography (CT), and the degree of difference of the cephalometric measurements. CT images of 16 adult patients with normal class I occlusion were sent to personal computer and reconstructed into 3D images using V-Works 3.5{sup TM} (Cybermed Inc., Seoul, Korea). With the internal program of V-Works 3.5{sup TM}, 12 landmarks on regular cephalograms were transformed into 21 analytic categories and measured by 2 observers and in addition, one of the observers repeated their measurements. Intra-observer difference was calculated using paired t-test, and inter-observer by two sample test. There were significant differences in the intra-observer measurements (p<0.05) in four of the categories which included ANS-Me, ANS-PNS, Cdl-GO (Lt), GoL-GoR, but with the exception of Cdl-Go (Lt), ZmL-ZmR, Zyo-Zyo, the average differences were within 2 mm of each other. The inter-observer observations also showed significant differences in the measurements of the ZmL-ZmR and Zyo-Zyo categories (p<0.05). With the exception of the Cdl-Me (Rt), ZmL-ZmR, Zyo-Zyo categories, the average differences between the two observers were within 2mm, but the ZmL-ZmR and Zyo-Zyo values differed greatly with values of 8.10 and 19.8 mm respectively. In general, 3D CT images showed greater accuracy and reproducibility, with the exception of suture areas such as Zm and Zyo, than regular cephalograms in orthodontic measurement, showing differences of less than 2 mm, therefore 3D CT images can be useful in cephalometric measurements and treatment planning.

  12. Three dimensional tracking for volumetric spectral-domain optical coherence tomography.

    Science.gov (United States)

    Maguluri, Gopi; Mujat, Mircea; Park, B H; Kim, K H; Sun, Wei; Iftimia, N V; Ferguson, R D; Hammer, Daniel X; Chen, Teresa C; de Boer, Johannes F

    2007-12-10

    We present a three-dimensional (3D) tracker for a clinical ophthalmic spectral domain optical coherence tomography (SD-OCT) system that combines depth-tracking with lateral tracking, providing a stabilized reference frame for 3D data recording and post acquisition analysis. The depth-tracking system is implemented through a real-time dynamic feedback mechanism to compensate for motion artifact in the axial direction. Active monitoring of the retina and adapting the reference arm of the interferometer allowed the whole thickness of the retina to be stabilized to within +/-100 mum. We achieve a relatively constant SNR from image to image by stabilizing the image of the retina with respect to the depth dependent sensitivity of SD-OCT. The depth tracking range of our system is 5.2 mm in air and the depth is adjusted every frame.nhancement in the stability of the images with the depth-tracking algorithm is demonstrated on a healthy volunteer.

  13. Three-Dimensional Imaging Using Microcomputed Tomography For Studying Gaharu Morphology

    International Nuclear Information System (INIS)

    Yazid, Khair'iah; Bin Awang, Mat Rasol; Mohamed, Abdul Aziz; Bin Hj Khalid, Mohd Ashhar; Masschaele, Bert; Abdullah, Mohd. Zaid; Saleh, Junita Mohamad

    2010-01-01

    To demonstrates the potential application of the high resolution X-ray micro-CT technique in the analysis of internal structure in Gaharu wood. Gaharu or internationally, Agar wood, is known for its fragrant resinous wood. The hardware device used in this study was an X-ray micro-CT scanner at Center of Tomography (UGCT), CT facility in Ghent University, Belgium. This technique allows the 3D investigation of the internal structure of the wood in a non-destructive way. Most of the data analysis was done with the software VG Studio Max and MATLAB. Here we present some preliminary results from three-dimensional images from a piece of high grade Gaharu. Micro-CT images of the specimens were obtained at 7 μm resolution. Besides a clear distinction between pores and material, some bright white areas occur in the reconstruction images. Not only the volume visualization is helpful, morphological parameters of open-pores and dark resins are calculated from these 3D data set. The micro-CT technique is a valid support for evaluating the pores structure and resin distribution in Gaharu.

  14. Imaging pathways in fractured rock using three-dimensional electrical resistivity tomography

    Science.gov (United States)

    Robinson, Judith; Slater, Lee; Johnson, Timothy B.; Shapiro, Allen M.; Tiedeman, Claire; Ntlargiannis, Dimitrios; Johnson, Carole D.; Day-Lewis, Frederick D.; Lacombe, Pierre; Imbrigiotta, Thomas; Lane, John W.

    2016-01-01

    Major challenges exist in delineating bedrock fracture zones because these cause abrupt changes in geological and hydrogeological properties over small distances. Borehole observations cannot sufficiently capture heterogeneity in these systems. Geophysical techniques offer the potential to image properties and processes in between boreholes. We used three-dimensional cross borehole electrical resistivity tomography (ERT) in a 9 m (diameter) × 15 m well field to capture high-resolution flow and transport processes in a fractured mudstone contaminated by chlorinated solvents, primarily trichloroethylene. Conductive (sodium bromide) and resistive (deionized water) injections were monitored in seven boreholes. Electrode arrays with isolation packers and fluid sampling ports were designed to enable acquisition of ERT measurements during pulsed tracer injections. Fracture zone locations and hydraulic pathways inferred from hydraulic head drawdown data were compared with electrical conductivity distributions from ERT measurements. Static ERT imaging has limited resolution to decipher individual fractures; however, these images showed alternating conductive and resistive zones, consistent with alternating laminated and massive mudstone units at the site. Tracer evolution and migration was clearly revealed in time-lapse ERT images and supported by in situ borehole vertical apparent conductivity profiles collected during the pulsed tracer test. While water samples provided important local information at the extraction borehole, ERT delineated tracer migration over spatial scales capturing the primary hydrogeological heterogeneity controlling flow and transport. The fate of these tracer injections at this scale could not have been quantified using borehole logging and/or borehole sampling methods alone.

  15. The assessment of orthodontic bonding defects: optical coherence tomography followed by three-dimensional reconstruction

    Science.gov (United States)

    Rominu, R.; Sinescu, C.; Rominu, M.; Negrutiu, M.; Petrescu, E.; Pop, D.; Podoleanu, A. Gh.

    2011-10-01

    Orthodontic bonding is a simple yet important procedure that can influence the outcome of treatment in case it is performed incorrectly. An orthodontic treatment shadowed by repeated bonding failures can become unduly long and will decrease patient trust and compliance. Optical coherence tomography has been widely used in ophtalmology but is relatively new to dentistry. Using OCT one can detect aerial inclusions within the orthodontic adhesive or even identify incongruence between the bracket base and the tooth surface. The aim of our study was to identify bonding defects and reconstruct them three-dimensionally in order to be able to characterize them more accurately. We bonded 30 sound human permanent teeth with ceramic orthodontic brackets using a no-mix self-curing orthodontic adhesive. Prior to bonding all teeth were stored in tap water at 4°C and then professionally cleaned with rotary brushes and pumice. The samples were processed by the same person and the rotary brushes were changed after every fifth tooth. All interfaces were investigated by means of OCT and 4 defects were found. Subsequently, the defects were reconstructed threedimensionally using an open-source program. By identifying and reconstructing bonding defects we could assess the quality of the bonding procedure. Since bonding tends to be more accurate in vitro where the environmental conditions are close to ideal, it is probable that defects found in vivo be even greater in number, which leads to the conclusion that this type of investigation is potentially valuable.

  16. Quantitative performance characterization of three-dimensional noncontact fluorescence molecular tomography

    Science.gov (United States)

    Favicchio, Rosy; Psycharakis, Stylianos; Schönig, Kai; Bartsch, Dusan; Mamalaki, Clio; Papamatheakis, Joseph; Ripoll, Jorge; Zacharakis, Giannis

    2016-02-01

    Fluorescent proteins and dyes are routine tools for biological research to describe the behavior of genes, proteins, and cells, as well as more complex physiological dynamics such as vessel permeability and pharmacokinetics. The use of these probes in whole body in vivo imaging would allow extending the range and scope of current biomedical applications and would be of great interest. In order to comply with a wide variety of application demands, in vivo imaging platform requirements span from wide spectral coverage to precise quantification capabilities. Fluorescence molecular tomography (FMT) detects and reconstructs in three dimensions the distribution of a fluorophore in vivo. Noncontact FMT allows fast scanning of an excitation source and noninvasive measurement of emitted fluorescent light using a virtual array detector operating in free space. Here, a rigorous process is defined that fully characterizes the performance of a custom-built horizontal noncontact FMT setup. Dynamic range, sensitivity, and quantitative accuracy across the visible spectrum were evaluated using fluorophores with emissions between 520 and 660 nm. These results demonstrate that high-performance quantitative three-dimensional visible light FMT allowed the detection of challenging mesenteric lymph nodes in vivo and the comparison of spectrally distinct fluorescent reporters in cell culture.

  17. Three-dimensional simultaneous optical coherence tomography and confocal fluorescence microscopy for investigation of lung tissue.

    Science.gov (United States)

    Gaertner, Maria; Cimalla, Peter; Meissner, Sven; Kuebler, Wolfgang M; Koch, Edmund

    2012-07-01

    Although several strategies exist for a minimal-invasive treatment of patients with lung failure, the mortality rate of acute respiratory distress syndrome still reaches 30% at minimum. This striking number indicates the necessity of understanding lung dynamics on an alveolar level. To investigate the dynamical behavior on a microscale, we used three-dimensional geometrical and functional imaging to observe tissue parameters including alveolar size and length of embedded elastic fibers during ventilation. We established a combined optical coherence tomography (OCT) and confocal fluorescence microscopy system that is able to monitor the distension of alveolar tissue and elastin fibers simultaneously within three dimensions. The OCT system can laterally resolve a 4.9 μm line pair feature and has an approximately 11 μm full-width-half-maximum axial resolution in air. confocal fluorescence microscopy visualizes molecular properties of the tissue with a resolution of 0.75 μm (laterally), and 5.9 μm (axially) via fluorescence detection of the dye sulforhodamine B specifically binding to elastin. For system evaluation, we used a mouse model in situ to perform lung distension by application of different constant pressure values within the physiological regime. Our method enables the investigation of alveolar dynamics by helping to reveal basic processes emerging during artificial ventilation and breathing.

  18. Compressed sampling for boundary measurements in three-dimensional electrical impedance tomography

    International Nuclear Information System (INIS)

    Javaherian, Ashkan; Soleimani, Manuchehr

    2013-01-01

    Electrical impedance tomography (EIT) utilizes electrodes on a medium's surface to produce measured data from which the conductivity distribution inside the medium is estimated. For the cases that relocation of electrodes is impractical or no a priori assumptions can be made to optimize the electrodes placement, a large number of electrodes may be needed to cover all possible imaging volume. This may occur in dynamically varying conductivity distribution in 3D EIT. Three-dimensional EIT then requires inverting very large linear systems to calculate the conductivity field, which causes significant problems regarding storage space and reconstruction time in addition to that data acquisition for a large number of electrodes will reduce the achievable frame rate, which is considered as major advantage of EIT imaging. This study proposes an idea to reduce the reconstruction complexity based on the well-known compressed sampling theory. By applying the so-called model-based CoSaMP algorithm to large size data collected by a 256 channel system, the size of forward operator and data acquisition time is reduced to those of a 32 channel system, while accuracy of reconstruction is significantly improved. The results demonstrate great capability of compressed sampling for overriding the challenges arising in 3D EIT. (paper)

  19. Computational strategies for three-dimensional flow simulations on distributed computer systems

    Science.gov (United States)

    Sankar, Lakshmi N.; Weed, Richard A.

    1995-08-01

    This research effort is directed towards an examination of issues involved in porting large computational fluid dynamics codes in use within the industry to a distributed computing environment. This effort addresses strategies for implementing the distributed computing in a device independent fashion and load balancing. A flow solver called TEAM presently in use at Lockheed Aeronautical Systems Company was acquired to start this effort. The following tasks were completed: (1) The TEAM code was ported to a number of distributed computing platforms including a cluster of HP workstations located in the School of Aerospace Engineering at Georgia Tech; a cluster of DEC Alpha Workstations in the Graphics visualization lab located at Georgia Tech; a cluster of SGI workstations located at NASA Ames Research Center; and an IBM SP-2 system located at NASA ARC. (2) A number of communication strategies were implemented. Specifically, the manager-worker strategy and the worker-worker strategy were tested. (3) A variety of load balancing strategies were investigated. Specifically, the static load balancing, task queue balancing and the Crutchfield algorithm were coded and evaluated. (4) The classical explicit Runge-Kutta scheme in the TEAM solver was replaced with an LU implicit scheme. And (5) the implicit TEAM-PVM solver was extensively validated through studies of unsteady transonic flow over an F-5 wing, undergoing combined bending and torsional motion. These investigations are documented in extensive detail in the dissertation, 'Computational Strategies for Three-Dimensional Flow Simulations on Distributed Computing Systems', enclosed as an appendix.

  20. Computational strategies for three-dimensional flow simulations on distributed computer systems

    Science.gov (United States)

    Sankar, Lakshmi N.; Weed, Richard A.

    1995-01-01

    This research effort is directed towards an examination of issues involved in porting large computational fluid dynamics codes in use within the industry to a distributed computing environment. This effort addresses strategies for implementing the distributed computing in a device independent fashion and load balancing. A flow solver called TEAM presently in use at Lockheed Aeronautical Systems Company was acquired to start this effort. The following tasks were completed: (1) The TEAM code was ported to a number of distributed computing platforms including a cluster of HP workstations located in the School of Aerospace Engineering at Georgia Tech; a cluster of DEC Alpha Workstations in the Graphics visualization lab located at Georgia Tech; a cluster of SGI workstations located at NASA Ames Research Center; and an IBM SP-2 system located at NASA ARC. (2) A number of communication strategies were implemented. Specifically, the manager-worker strategy and the worker-worker strategy were tested. (3) A variety of load balancing strategies were investigated. Specifically, the static load balancing, task queue balancing and the Crutchfield algorithm were coded and evaluated. (4) The classical explicit Runge-Kutta scheme in the TEAM solver was replaced with an LU implicit scheme. And (5) the implicit TEAM-PVM solver was extensively validated through studies of unsteady transonic flow over an F-5 wing, undergoing combined bending and torsional motion. These investigations are documented in extensive detail in the dissertation, 'Computational Strategies for Three-Dimensional Flow Simulations on Distributed Computing Systems', enclosed as an appendix.

  1. Three-dimensional grain structure of sintered bulk strontium titanate from X-ray diffraction contrast tomography

    DEFF Research Database (Denmark)

    Syha, M.; Rheinheimer, W.; Bäurer, M.

    2012-01-01

    The three-dimensional grain boundary network of sintered bulk strontium titanate is reconstructed using X-ray diffraction contrast tomography, a non-destructive technique for determining the grain shape and crystallographic orientation in polycrystals that is ideally suited for detailed studies...

  2. Discrete imaging models for three-dimensional optoacoustic tomography using radially symmetric expansion functions.

    Science.gov (United States)

    Wang, Kun; Schoonover, Robert W; Su, Richard; Oraevsky, Alexander; Anastasio, Mark A

    2014-05-01

    Optoacoustic tomography (OAT), also known as photoacoustic tomography, is an emerging computed biomedical imaging modality that exploits optical contrast and ultrasonic detection principles. Iterative image reconstruction algorithms that are based on discrete imaging models are actively being developed for OAT due to their ability to improve image quality by incorporating accurate models of the imaging physics, instrument response, and measurement noise. In this work, we investigate the use of discrete imaging models based on Kaiser-Bessel window functions for iterative image reconstruction in OAT. A closed-form expression for the pressure produced by a Kaiser-Bessel function is calculated, which facilitates accurate computation of the system matrix. Computer-simulation and experimental studies are employed to demonstrate the potential advantages of Kaiser-Bessel function-based iterative image reconstruction in OAT.

  3. Three-dimensional demonstration of liver and spleen by computer graphics technique

    International Nuclear Information System (INIS)

    Kashiwagi, Toru; Azuma, Masayoshi; Katayama, Kazuhiro; Yoshioka, Hiroaki; Ishizu, Hiromi; Mitsutani, Natsuki; Koizumi, Takao; Takayama, Ichiro

    1987-01-01

    Three-dimensional demonstration system of the liver and spleen has been developed using computer graphics technique. Three-dimensional models were constructed from CT images of the organ surface. The three-dimensional images were displayed as wire-frame and/or solid models on the color CRT. The anatomical surface of the liver and spleen was realistically viewed from any direction. In liver cirrhosis, atrophy of the right lobe, hypertrophy of the left lobe and splenomegaly were displayed vividly. The liver and hepatoma were displayed as wire-frame and solid models respectively on the same image. This combined display clarified the intrahepatic location of hepatoma together with configuration of liver and hepatoma. Furthermore, superimposed display of three dimensional models and celiac angiogram enabled us to understand the location and configuration of lesions more easily than the original CT data or angiogram alone. Therefore, it is expected that this system is clinically useful for noninvasive evaluation of patho-morphological changes of the liver and spleen. (author)

  4. Imaging Pathways in Fractured Rock Using Three-Dimensional Electrical Resistivity Tomography.

    Science.gov (United States)

    Robinson, Judith; Slater, Lee; Johnson, Timothy; Shapiro, Allen; Tiedeman, Claire; Ntarlagiannis, Dimitrios; Johnson, Carole; Day-Lewis, Frederick; Lacombe, Pierre; Imbrigiotta, Thomas; Lane, John

    2016-03-01

    Major challenges exist in delineating bedrock fracture zones because these cause abrupt changes in geological and hydrogeological properties over small distances. Borehole observations cannot sufficiently capture heterogeneity in these systems. Geophysical techniques offer the potential to image properties and processes in between boreholes. We used three-dimensional cross borehole electrical resistivity tomography (ERT) in a 9 m (diameter) × 15 m well field to capture high-resolution flow and transport processes in a fractured mudstone contaminated by chlorinated solvents, primarily trichloroethylene. Conductive (sodium bromide) and resistive (deionized water) injections were monitored in seven boreholes. Electrode arrays with isolation packers and fluid sampling ports were designed to enable acquisition of ERT measurements during pulsed tracer injections. Fracture zone locations and hydraulic pathways inferred from hydraulic head drawdown data were compared with electrical conductivity distributions from ERT measurements. Static ERT imaging has limited resolution to decipher individual fractures; however, these images showed alternating conductive and resistive zones, consistent with alternating laminated and massive mudstone units at the site. Tracer evolution and migration was clearly revealed in time-lapse ERT images and supported by in situ borehole vertical apparent conductivity profiles collected during the pulsed tracer test. While water samples provided important local information at the extraction borehole, ERT delineated tracer migration over spatial scales capturing the primary hydrogeological heterogeneity controlling flow and transport. The fate of these tracer injections at this scale could not have been quantified using borehole logging and/or borehole sampling methods alone. © 2015, National Ground Water Association.

  5. Optimal distance of multi-plane sensor in three-dimensional electrical impedance tomography.

    Science.gov (United States)

    Hao, Zhenhua; Yue, Shihong; Sun, Benyuan; Wang, Huaxiang

    2017-12-01

    Electrical impedance tomography (EIT) is a visual imaging technique for obtaining the conductivity and permittivity distributions in the domain of interest. As an advanced technique, EIT has the potential to be a valuable tool for continuously bedside monitoring of pulmonary function. The EIT applications in any three-dimensional (3 D) field are very limited to the 3 D effects, i.e. the distribution of electric field spreads far beyond the electrode plane. The 3 D effects can result in measurement errors and image distortion. An important way to overcome the 3 D effect is to use the multiple groups of sensors. The aim of this paper is to find the best space resolution of EIT image over various electrode planes and select an optimal plane spacing in a 3 D EIT sensor, and provide guidance for 3 D EIT electrodes placement in monitoring lung function. In simulation and experiment, several typical conductivity distribution models, such as one rod (central, midway and edge), two rods and three rods, are set at different plane spacings between the two electrode planes. A Tikhonov regularization algorithm is utilized for reconstructing the images; the relative error and the correlation coefficient are utilized for evaluating the image quality. Based on numerical simulation and experimental results, the image performance at different spacing conditions is evaluated. The results demonstrate that there exists an optimal plane spacing between the two electrode planes for 3 D EIT sensor. And then the selection of the optimal plane spacing between the electrode planes is suggested for the electrodes placement of multi-plane EIT sensor.

  6. Three-dimensional distributions of elements in biological samples by energy-filtered electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Leapman, R.D.; Kocsis, E.; Zhang, G.; Talbot, T.L.; Laquerriere, P

    2004-07-15

    By combining electron tomography with energy-filtered electron microscopy, we have shown the feasibility of determining the three-dimensional distributions of phosphorus in biological specimens. Thin sections of the nematode, Caenorhabditis elegans were prepared by high-pressure freezing, freeze-substitution and plastic embedding. Images were recorded at energy losses above and below the phosphorus L{sub 2,3} edge using a post-column imaging filter operating at a beam energy of 120 keV. The unstained specimens exhibited minimal contrast in bright-field images. After it was determined that the specimen was sufficiently thin to allow two-window ratio imaging of phosphorus, pairs of pre-edge and post-edge images were acquired in series over a tilt range of {+-}55 deg. at 5 deg. increments for two orthogonal tilt axes. The projected phosphorus distributions were aligned using the pre-edge images that contained inelastic contrast from colloidal gold particles deposited on the specimen surface. A reconstruction and surface rendering of the phosphorus distribution clearly revealed features 15-20 nm in diameter, which were identified as ribosomes distributed along the stacked membranes of endoplasmic reticulum and in the cytoplasm. The sensitivity of the technique was estimated at <35 phosphorus atoms per voxel based on the known total ribosomal phosphorus content of approximately 7000 atoms. Although a high electron dose of approximately 10{sup 7} e/nm{sup 2} was required to record two-axis tilt series, specimens were sufficiently stable to allow image alignment and tomographic reconstruction.

  7. Local detection of three-dimensional inclusions in electrical impedance tomography

    International Nuclear Information System (INIS)

    Ide, T; Isozaki, H; Nakata, S; Siltanen, S

    2010-01-01

    Assume one is given a three-dimensional bounded domain with an unknown conductivity distribution inside. Further, suppose that the conductivity consists of a known background and unknown anomalous regions (inclusions) where conductivity values are unknown and different from the background. A method is introduced in Ide et al (2007 Commun. Pure Appl. Math. 60 1415–42) for locating inclusions approximately from noisy localized voltage-to-current measurements performed at the boundary of the body. The method is based on the use of complex geometrical optics solutions and hyperbolic geometry; numerical testing is presented in the aforementioned paper for the two-dimensional case. This work reports the results of computational implementation of the method in dimension three, where both the simulation of data and the computerized inversion algorithm are more complicated than in dimension two. Three new regularizing steps are added to the algorithm, resulting in significantly better robustness against noise. Numerical experiments are reported, suggesting that the approximate location of the inclusions can be reliably recovered from the data with a realistic level of measurement noise. Potential applications of the results include early diagnosis of breast cancer, underground contaminant detection and nondestructive testing

  8. Three-dimensional forward solver and its performance analysis for magnetic resonance electrical impedance tomography (MREIT) using recessed electrodes

    International Nuclear Information System (INIS)

    Lee, Byung Il; Oh, Suk Hoon; Woo, Eung Je; Lee, Soo Yeol; Cho, Min Hyoung; Kwon, Ohin; Seo, Jin Keun; Lee, June-Yub; Baek, Woon Sik

    2003-01-01

    In magnetic resonance electrical impedance tomography (MREIT), we try to reconstruct a cross-sectional resistivity (or conductivity) image of a subject. When we inject a current through surface electrodes, it generates a magnetic field. Using a magnetic resonance imaging (MRI) scanner, we can obtain the induced magnetic flux density from MR phase images of the subject. We use recessed electrodes to avoid undesirable artefacts near electrodes in measuring magnetic flux densities. An MREIT image reconstruction algorithm produces cross-sectional resistivity images utilizing the measured internal magnetic flux density in addition to boundary voltage data. In order to develop such an image reconstruction algorithm, we need a three-dimensional forward solver. Given injection currents as boundary conditions, the forward solver described in this paper computes voltage and current density distributions using the finite element method (FEM). Then, it calculates the magnetic flux density within the subject using the Biot-Savart law and FEM. The performance of the forward solver is analysed and found to be enough for use in MREIT for resistivity image reconstructions and also experimental designs and validations. The forward solver may find other applications where one needs to compute voltage, current density and magnetic flux density distributions all within a volume conductor

  9. High-performance blob-based iterative three-dimensional reconstruction in electron tomography using multi-GPUs

    Directory of Open Access Journals (Sweden)

    Wan Xiaohua

    2012-06-01

    Full Text Available Abstract Background Three-dimensional (3D reconstruction in electron tomography (ET has emerged as a leading technique to elucidate the molecular structures of complex biological specimens. Blob-based iterative methods are advantageous reconstruction methods for 3D reconstruction in ET, but demand huge computational costs. Multiple graphic processing units (multi-GPUs offer an affordable platform to meet these demands. However, a synchronous communication scheme between multi-GPUs leads to idle GPU time, and a weighted matrix involved in iterative methods cannot be loaded into GPUs especially for large images due to the limited available memory of GPUs. Results In this paper we propose a multilevel parallel strategy combined with an asynchronous communication scheme and a blob-ELLR data structure to efficiently perform blob-based iterative reconstructions on multi-GPUs. The asynchronous communication scheme is used to minimize the idle GPU time so as to asynchronously overlap communications with computations. The blob-ELLR data structure only needs nearly 1/16 of the storage space in comparison with ELLPACK-R (ELLR data structure and yields significant acceleration. Conclusions Experimental results indicate that the multilevel parallel scheme combined with the asynchronous communication scheme and the blob-ELLR data structure allows efficient implementations of 3D reconstruction in ET on multi-GPUs.

  10. 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

  11. Computed tomography

    International Nuclear Information System (INIS)

    Andre, M.; Resnick, D.

    1988-01-01

    Computed tomography (CT) has matured into a reliable and prominent tool for study of the muscoloskeletal system. When it was introduced in 1973, it was unique in many ways and posed a challenge to interpretation. It is in these unique features, however, that its advantages lie in comparison with conventional techniques. These advantages will be described in a spectrum of important applications in orthopedics and rheumatology

  12. A computational model for three-dimensional jointed media with a single joint set

    International Nuclear Information System (INIS)

    Koteras, J.R.

    1994-02-01

    This report describes a three-dimensional model for jointed rock or other media with a single set of joints. The joint set consists of evenly spaced joint planes. The normal joint response is nonlinear elastic and is based on a rational polynomial. Joint shear stress is treated as being linear elastic in the shear stress versus slip displacement before attaining a critical stress level governed by a Mohr-Coulomb faction criterion. The three-dimensional model represents an extension of a two-dimensional, multi-joint model that has been in use for several years. Although most of the concepts in the two-dimensional model translate in a straightforward manner to three dimensions, the concept of slip on the joint planes becomes more complex in three dimensions. While slip in two dimensions can be treated as a scalar quantity, it must be treated as a vector in the joint plane in three dimensions. For the three-dimensional model proposed here, the slip direction is assumed to be the direction of maximum principal strain in the joint plane. Five test problems are presented to verify the correctness of the computational implementation of the model

  13. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  14. 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

  15. Multi-scale computational model of three-dimensional hemodynamics within a deformable full-body arterial network

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Nan [Department of Bioengineering, Stanford University, Stanford, CA 94305 (United States); Department of Biomedical Engineering, King’s College London, London SE1 7EH (United Kingdom); Humphrey, Jay D. [Department of Biomedical Engineering, Yale University, New Haven, CT 06520 (United States); Figueroa, C. Alberto, E-mail: alberto.figueroa@kcl.ac.uk [Department of Biomedical Engineering, King’s College London, London SE1 7EH (United Kingdom)

    2013-07-01

    In this article, we present a computational multi-scale model of fully three-dimensional and unsteady hemodynamics within the primary large arteries in the human. Computed tomography image data from two different patients were used to reconstruct a nearly complete network of the major arteries from head to foot. A linearized coupled-momentum method for fluid–structure-interaction was used to describe vessel wall deformability and a multi-domain method for outflow boundary condition specification was used to account for the distal circulation. We demonstrated that physiologically realistic results can be obtained from the model by comparing simulated quantities such as regional blood flow, pressure and flow waveforms, and pulse wave velocities to known values in the literature. We also simulated the impact of age-related arterial stiffening on wave propagation phenomena by progressively increasing the stiffness of the central arteries and found that the predicted effects on pressure amplification and pulse wave velocity are in agreement with findings in the clinical literature. This work demonstrates the feasibility of three-dimensional techniques for simulating hemodynamics in a full-body compliant arterial network.

  16. Three-dimensional hard and soft tissue imaging of the human cochlea by scanning laser optical tomography (SLOT.

    Directory of Open Access Journals (Sweden)

    Nadine Tinne

    Full Text Available The present study focuses on the application of scanning laser optical tomography (SLOT for visualization of anatomical structures inside the human cochlea ex vivo. SLOT is a laser-based highly efficient microscopy technique which allows for tomographic imaging of the internal structure of transparent specimens. Thus, in the field of otology this technique is best convenient for an ex vivo study of the inner ear anatomy. For this purpose, the preparation before imaging comprises decalcification, dehydration as well as optical clearing of the cochlea samples in toto. Here, we demonstrate results of SLOT imaging visualizing hard and soft tissue structures with an optical resolution of down to 15 μm using extinction and autofluorescence as contrast mechanisms. Furthermore, the internal structure can be analyzed nondestructively and quantitatively in detail by sectioning of the three-dimensional datasets. The method of X-ray Micro Computed Tomography (μCT has been previously applied to explanted cochlea and is solely based on absorption contrast. An advantage of SLOT is that it uses visible light for image formation and thus provides a variety of contrast mechanisms known from other light microscopy techniques, such as fluorescence or scattering. We show that SLOT data is consistent with μCT anatomical data and provides additional information by using fluorescence. We demonstrate that SLOT is applicable for cochlea with metallic cochlear implants (CI that would lead to significant artifacts in μCT imaging. In conclusion, the present study demonstrates the capability of SLOT for resolution visualization of cleared human cochleae ex vivo using multiple contrast mechanisms and lays the foundation for a broad variety of additional studies.

  17. On three-dimensional nuclear thermo-hydraulic computation techniques for ATR

    International Nuclear Information System (INIS)

    1997-08-01

    The three-dimensional computation code for nuclear thermo-hydraulic combination core LAYMON-2A is used for the calculation of the power distribution and the control rod reactivity value of the ATR. This code possesses various functions which are required for planning the core operation such as the search function for critical boric acid concentration, and can do various simulation calculations such as core burning calculation. Further, the three-dimensional analysis code for xenon dynamic characteristics in the core LAYMON-2C, in which the dynamic characteristic equation of xenon-samarium was incorporated into the LAYMON-2A code can take the change with time lapse of xenon-samarium concentration accompanying the change of power level and power distribution into account, and it is used for the analysis of the spatial vibration characteristics of power and the regional power control characteristics due to xenon in the core. As to the LAYMON-2A, the computation flow, power distribution and thermo-hydraulic computation models, and critical search function are explained. As to the LAYMON-2C, the computation flow is described. The comparison of the calculated values by using the LAYMON-2A code and the operation data of the Fugen is reported. (K.I.)

  18. A computer-based biomechanical analysis of the three-dimensional motion of cementless hip prostheses.

    Science.gov (United States)

    Gilbert, J L; Bloomfeld, R S; Lautenschlager, E P; Wixson, R L

    1992-04-01

    A computer-based mathematical technique was developed to measure and completely describe the migration and micromotion of a femoral hip prosthesis relative to the femur. This technique utilized the mechanics of rigid-body motion analysis and apparatus of seven linear displacement transducers to measure and describe the complete three-dimensional motion of the prosthesis during cyclic loading. Computer acquisition of the data and custom analysis software allowed one to calculate the magnitude and direction of the motion of any point of interest on the prostheses from information about the motion of two points on the device. The data were also used to replay the tests using a computer animation technique, which allowed a magnified view of the three-dimensional motion of the prosthesis. This paper describes the mathematical development of the rigid-body motion analysis, the experimental method and apparatus for data collection, the technique used to animate the motion, the sources of error and the effect of the assumptions (rigid bodies) on the results. Selected results of individual test runs of uncemented and cemented prostheses are presented to demonstrate the efficacy of the method. The combined effect of the vibration and electrical noise resulted in a resolution of the system of about 3-5 microns motion for each transducer. Deformation effects appear to contribute about 3-15 microns to the measurement error. This measurement and analysis technique is a very sensitive and powerful means of assessing the effects of different design parameters on the migration and micromotion of total joint prostheses and can be applied to any other case (knee, dental implant) where three-dimensional relative motion between two bodies is important.

  19. An improved method for computer generation of three-dimensional digital holography

    International Nuclear Information System (INIS)

    Hu, Yanlei; Chen, Yuhang; Li, Jiawen; Huang, Wenhao; Chu, Jiaru; Ma, Jianqiang

    2013-01-01

    A novel method is proposed for designing optimized three-dimensional computer-generated holograms (CGHs). A series of spherical wave factors are introduced into the conventional optimal rotation angle (ORA) algorithm to achieve a varying amount of defocus along the optical axis, and the distraction terms are minimized during the iterative process. Both numerical simulation and experimental reconstructions are presented to demonstrate that this method is able to yield excellent multilayer patterns with high uniformity and signal-to-noise ratio (SNR). This method is significant for applications in laser 3D printing and multilayer data recording. (paper)

  20. Computation of zero. beta. three-dimensional equilibria with magnetic islands

    Energy Technology Data Exchange (ETDEWEB)

    Reiman, A.H.; Greenside, H.S.

    1989-01-01

    A Picard iteration scheme has been implemented for the computation of toroidal, fully three-dimensional, zero ..beta.. equilibria with islands and stochastic regions. Representation of the variables in appropriate coordinate systems has been found to be a key to making the scheme work well. In particular, different coordinate systems are used for solving magnetic differential equations and Ampere's law. The current profile is adjusted when islands and stochastic regions appear. An underrelaxation of the current profile modifications is generally needed for stable iteration of the algorithm. Some examples of equilibrium calculations are presented. 16 refs., 6 figs., 1 tab.

  1. Computer codes for three dimensional mass transport with non-linear sorption

    International Nuclear Information System (INIS)

    Noy, D.J.

    1985-03-01

    The report describes the mathematical background and data input to finite element programs for three dimensional mass transport in a porous medium. The transport equations are developed and sorption processes are included in a general way so that non-linear equilibrium relations can be introduced. The programs are described and a guide given to the construction of the required input data sets. Concluding remarks indicate that the calculations require substantial computer resources and suggest that comprehensive preliminary analysis with lower dimensional codes would be important in the assessment of field data. (author)

  2. Three-dimensional turbulent swirling flow in a cylinder: Experiments and computations

    International Nuclear Information System (INIS)

    Gupta, Amit; Kumar, Ranganathan

    2007-01-01

    Dynamics of the three-dimensional flow in a cyclone with tangential inlet and tangential exit were studied using particle tracking velocimetry (PTV) and a three-dimensional computational model. The PTV technique is described in this paper and appears to be well suited for the current flow situation. The flow was helical in nature and a secondary recirculating flow was observed and well predicted by computations using the RNG k-ε turbulence model. The secondary flow was characterized by a single vortex which circulated around the axis and occupied a large fraction of the cylinder diameter. The locus of the vortex center meandered around the cylinder axis, making one complete revolution for a cylinder aspect ratio of 2. Tangential velocities from both experiments and computations were compared and found to be in good agreement. The general structure of the flow does not vary significantly as the Reynolds number is increased. However, slight changes in all components of velocity and pressure were seen as the inlet velocity is increased. By increasing the inlet aspect ratio it was observed that the vortex meandering changed significantly

  3. Three-dimensional turbulent swirling flow in a cylinder: Experiments and computations

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Amit [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Kumar, Ranganathan [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States)]. E-mail: rnkumar@mail.ucf.edu

    2007-04-15

    Dynamics of the three-dimensional flow in a cyclone with tangential inlet and tangential exit were studied using particle tracking velocimetry (PTV) and a three-dimensional computational model. The PTV technique is described in this paper and appears to be well suited for the current flow situation. The flow was helical in nature and a secondary recirculating flow was observed and well predicted by computations using the RNG k-{epsilon} turbulence model. The secondary flow was characterized by a single vortex which circulated around the axis and occupied a large fraction of the cylinder diameter. The locus of the vortex center meandered around the cylinder axis, making one complete revolution for a cylinder aspect ratio of 2. Tangential velocities from both experiments and computations were compared and found to be in good agreement. The general structure of the flow does not vary significantly as the Reynolds number is increased. However, slight changes in all components of velocity and pressure were seen as the inlet velocity is increased. By increasing the inlet aspect ratio it was observed that the vortex meandering changed significantly.

  4. Three dimensional computations of the flow around a LM19 rotor

    Energy Technology Data Exchange (ETDEWEB)

    Hambraeus, T. [FFA, Bromma (Sweden)

    1997-12-31

    To achieve insight in the flow phenomenon occurring in wind power engineering modeling of the flow through the basic governing equations, Navier-Stokes and Euler, can be a great complement to experiments and other computational methods such as the BEM (Blade Element Momentum). Navier-Stokes methods is regularly used in prediction of air-foil flows but then mostly under attached flow conditions. One of the main differences between air-foil computations for aircraft industry and computations for wind turbine applications is that the former is not very interested in separated flow while for the latter case this is part of the operating conditions. It has been noted that separated flow poses problems since the most popular turbulence models such as Baldwin-Lomax and the {kappa}-{epsilon} model seems to over estimate the amount of turbulent viscosity produced and thus suppressing the separation. The work with finding better turbulence models is presently an area with large amount of research offering improved models. However, in the present report only the two mentioned turbulence models have been used. The present report shows computational results obtained with the Navier-Stokes solver EU-RANUS. First the results from a two-dimensional verification cases are shown to verify that the solver produces results comparable with other solvers. The flow computed is attached flow and slightly separated flow over the so called Profile-A. Secondly three dimensional computations of the flow over a full three dimensional rotor at attached and stalled conditions is shown. The computed results are compared with measured power data from field experiments. (EG)

  5. Three-Dimensional Photoacoustic Tomography using Delay Multiply and Sum Beamforming Algorithm

    OpenAIRE

    Paridar, Roya; Mozaffarzadeh, Moein; Mahloojifar, Ali; Nasiriavanaki, Mohammadreza; Orooji, Mahdi

    2018-01-01

    Photoacoustic imaging (PAI), is a promising medical imaging technique that provides the high contrast of the optical imaging and the resolution of ultrasound (US) imaging. Among all the methods, Three-dimensional (3D) PAI provides a high resolution and accuracy. One of the most common algorithms for 3D PA image reconstruction is delay-and-sum (DAS). However, the quality of the reconstructed image obtained from this algorithm is not satisfying, having high level of sidelobes and a wide mainlob...

  6. FLICA-4 (version 1). A computer code for three dimensional thermal analysis of nuclear reactor cores

    International Nuclear Information System (INIS)

    Raymond, P.; Allaire, G.; Boudsocq, G.; Caruge, D.; Gramont, T. de; Toumi, I.

    1995-01-01

    FLICA-4 is a thermal-hydraulic computer code, developed at the French Atomic Energy Commission (CEA) for three-dimensional steady-state or transient two-phase flow, and aimed at design and safety thermal analysis of nuclear reactor cores. It is available for various UNIX workstations and CRAY computers under UNICOS.It is based on four balance equations which include three balance equations for the mixture and a mass balance equation for the less concentrated phase which allows for the calculation of non equilibrium flows such as sub-cooled boiling and superheated steam. A drift velocity model takes into account the velocity unbalance between phases. The equations are solved using a finite volume numerical scheme. Typical running time, specific features (coupling with other codes) and auxiliary programs are presented. 1 tab., 9 refs

  7. Hypertext and three-dimensional computer graphics in an all digital PC-based CAI workstation.

    Science.gov (United States)

    Schwarz, D. L.; Wind, G. G.

    1991-01-01

    In the past several years there has been an enormous increase in the number of computer-assisted instructional (CAI) applications. Many medical educators and physicians have recognized the power and utility of hypertext. Some developers have incorporated simple diagrams, scanned monochrome graphics or still frame photographs from a laser disc or CD-ROM into their hypertext applications. These technologies have greatly increased the role of the microcomputer in education and training. There still remain numerous applications for these tools which are yet to be explored. One of these exciting areas involves the use of three-dimensional computer graphics. An all digital platform increases application portability. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:1807767

  8. Three-dimensional range data compression using computer graphics rendering pipeline.

    Science.gov (United States)

    Zhang, Song

    2012-06-20

    This paper presents the idea of naturally encoding three-dimensional (3D) range data into regular two-dimensional (2D) images utilizing computer graphics rendering pipeline. The computer graphics pipeline provides a means to sample 3D geometry data into regular 2D images, and also to retrieve the depth information for each sampled pixel. The depth information for each pixel is further encoded into red, green, and blue color channels of regular 2D images. The 2D images can further be compressed with existing 2D image compression techniques. By this novel means, 3D geometry data obtained by 3D range scanners can be instantaneously compressed into 2D images, providing a novel way of storing 3D range data into its 2D counterparts. We will present experimental results to verify the performance of this proposed technique.

  9. POST: a postprocessor computer code for producing three-dimensional movies of two-phase flow in a reactor vessel

    International Nuclear Information System (INIS)

    Taggart, K.A.; Liles, D.R.

    1977-08-01

    The development of the TRAC computer code for analysis of LOCAs in light-water reactors involves the use of a three-dimensional (r-theta-z), two-fluid hydrodynamics model to describe the two-phase flow of steam and water through the reactor vessel. One of the major problems involved in interpreting results from this code is the presentation of three-dimensional flow patterns. The purpose of the report is to present a partial solution to this data display problem. A first version of a code which produces three-dimensional movies of flow in the reactor vessel has been written and debugged. This code (POST) is used as a postprocessor in conjunction with a stand alone three-dimensional two-phase hydrodynamics code (CYLTF) which is a test bed for the three-dimensional algorithms to be used in TRAC

  10. Lung nodule detection performance in five observers on computed tomography (CT) with adaptive iterative dose reduction using three-dimensional processing (AIDR 3D) in a Japanese multicenter study: Comparison between ultra-low-dose CT and low-dose CT by receiver-operating characteristic analysis.

    Science.gov (United States)

    Nagatani, Yukihiro; Takahashi, Masashi; Murata, Kiyoshi; Ikeda, Mitsuru; Yamashiro, Tsuneo; Miyara, Tetsuhiro; Koyama, Hisanobu; Koyama, Mitsuhiro; Sato, Yukihisa; Moriya, Hiroshi; Noma, Satoshi; Tomiyama, Noriyuki; Ohno, Yoshiharu; Murayama, Sadayuki

    2015-07-01

    To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 ± 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distributed rating in CT images at 20 mA (ULDCT) and 120 mA (LDCT). Receiver-operating characteristic (ROC) analysis was used to evaluate LNDP of both methods in total and also in subgroups classified by LD (>4, 6 and 8 mm) and nodular characteristics (solid and ground glass nodules). For SOR, 161 solid and 60 ground glass nodules were identified. No significant difference in LNDP for entire solid nodules was demonstrated between both methods, as area under ROC curve (AUC) was 0.844 ± 0.017 in ULDCT and 0.876 ± 0.026 in LDCT (p=0.057). For ground glass nodules with LD 8mm or more, LNDP was similar between both methods, as AUC 0.899 ± 0.038 in ULDCT and 0.941 ± 0.030 in LDCT. (p=0.144). ULDCT using AIDR3D with an equivalent radiation dose to chest x-ray could have comparable LNDP to LDCT with AIDR3D except for smaller ground

  11. Three dimensional computational fluid dynamic analysis of debris transport under emergency cooling water recirculation

    International Nuclear Information System (INIS)

    Park, Jong Woon

    2010-01-01

    This paper provides a computational fluid dynamic (CFD) analysis method on the evaluation of debris transport under emergency recirculation mode after loss of coolant accident of a nuclear power plant. Three dimensional reactor building floor geometrical model is constructed including flow obstacles larger than 6 inches such as mechanical components and equipments and considering various inlet flow paths from the upper reactor building such as break and spray flow. In the modeling of the inlet flows from the upper floors, effect of gravitational force was also reflected. For the precision of the analysis, 3 millions of tetrahedral-shaped meshes were generated. Reference calculation showed physically reasonable results. Sensitivity studies for mesh type and turbulence model showed very similar results to the reference case. This study provides useful information on the application of CFD to the evaluation of debris transport fraction for the design of new emergency sump filters. (orig.)

  12. Three dimensional field computation software package DE3D and its applications

    International Nuclear Information System (INIS)

    Fan Mingwu; Zhang Tianjue; Yan Weili

    1992-07-01

    A software package, DE3D that can be run on PC for three dimensional electrostatic and magnetostatic field analysis has been developed in CIAE (China Institute of Atomic Energy). Two scalar potential method and special numerical techniques have made the code with high precision. It can be used for electrostatic and magnetostatic fields computations with complex boundary conditions. In the most cases, the result accuracy is better than 1% comparing with the measured. In some situations, the results are more acceptable than the other codes because some tricks are used for the current integral. Typical examples, design of a cyclotron magnet and magnetic elements on its beam transport line, given in the paper show how the program helps the designer to improve the design of the product. The software package could bring advantages to the producers and designers

  13. Simulation of radiation effects on three-dimensional computer optical memories

    International Nuclear Information System (INIS)

    Moscovitch, M.; Emfietzoglou, D.

    1997-01-01

    A model was developed to simulate the effects of heavy charged-particle (HCP) radiation on the information stored in three-dimensional computer optical memories. The model is based on (i) the HCP track radial dose distribution, (ii) the spatial and temporal distribution of temperature in the track, (iii) the matrix-specific radiation-induced changes that will affect the response, and (iv) the kinetics of transition of photochromic molecules from the colored to the colorless isomeric form (bit flip). It is shown that information stored in a volume of several nanometers radius around the particle close-quote s track axis may be lost. The magnitude of the effect is dependent on the particle close-quote s track structure. copyright 1997 American Institute of Physics

  14. Computer-aided-design-model-assisted absolute three-dimensional shape measurement.

    Science.gov (United States)

    Li, Beiwen; Bell, Tyler; Zhang, Song

    2017-08-20

    Conventional three-dimensional (3D) shape measurement methods are typically generic to all types of objects. Yet, for many measurement conditions, such a level of generality is inessential when having the preknowledge of the object geometry. This paper introduces a novel adaptive algorithm for absolute 3D shape measurement with the assistance of the object computer-aided-design (CAD) model. The proposed algorithm includes the following major steps: (1) export the 3D point cloud data from the CAD model; (2) transform the CAD model into the camera perspective; (3) obtain a wrapped phase map from three phase-shifted fringe images; and (4) retrieve absolute phase and 3D geometry assisted by the CAD model. We demonstrate that if object CAD models are available, such an algorithm is efficient in recovering absolute 3D geometries of both simple and complex objects with only three phase-shifted fringe images.

  15. Simulation of radiation effects on three-dimensional computer optical memories

    Science.gov (United States)

    Moscovitch, M.; Emfietzoglou, D.

    1997-01-01

    A model was developed to simulate the effects of heavy charged-particle (HCP) radiation on the information stored in three-dimensional computer optical memories. The model is based on (i) the HCP track radial dose distribution, (ii) the spatial and temporal distribution of temperature in the track, (iii) the matrix-specific radiation-induced changes that will affect the response, and (iv) the kinetics of transition of photochromic molecules from the colored to the colorless isomeric form (bit flip). It is shown that information stored in a volume of several nanometers radius around the particle's track axis may be lost. The magnitude of the effect is dependent on the particle's track structure.

  16. Computational fluid dynamics in three dimensional angiography: Preliminary hemodynamic results of various proximal geometry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ha Youn; Park, Sung Tae; Bae, Won Kyoung; Goo, Dong Erk [Dept. of Radiology, Soonchunhyang University Hospital, Seoul (Korea, Republic of)

    2014-12-15

    We studied the influence of proximal geometry on the results of computational fluid dynamics (CFD). We made five models of different proximal geometry from three dimensional angiography of 63-year-old women with intracranial aneurysm. CFD results were analyzed as peak systolic velocity (PSV) at inlet and outlet as well as flow velocity profile at proximal level of internal carotid artery (ICA) aneurysm. Modified model of cavernous one with proximal tubing showed faster PSV at outlet than that at inlet. The PSV of outlets of other models were slower than that of inlets. The flow velocity profiles at immediate proximal to ICA aneurysm showed similar patterns in all models, suggesting that proximal vessel geometries could affect CFD results.

  17. Three-dimensional scene encryption and display based on computer-generated holograms.

    Science.gov (United States)

    Kong, Dezhao; Cao, Liangcai; Jin, Guofan; Javidi, Bahram

    2016-10-10

    An optical encryption and display method for a three-dimensional (3D) scene is proposed based on computer-generated holograms (CGHs) using a single phase-only spatial light modulator. The 3D scene is encoded as one complex Fourier CGH. The Fourier CGH is then decomposed into two phase-only CGHs with random distributions by the vector stochastic decomposition algorithm. Two CGHs are interleaved as one final phase-only CGH for optical encryption and reconstruction. The proposed method can support high-level nonlinear optical 3D scene security and complex amplitude modulation of the optical field. The exclusive phase key offers strong resistances of decryption attacks. Experimental results demonstrate the validity of the novel method.

  18. Analysis of rotary engine combustion processes based on unsteady, three-dimensional computations

    Science.gov (United States)

    Raju, M. S.; Willis, E. A.

    1990-01-01

    A new computer code was developed for predicting the turbulent and chemically reacting flows with sprays occurring inside of a stratified charge rotary engine. The solution procedure is based on an Eulerian Lagrangian approach where the unsteady, three-dimensional Navier-Stokes equations for a perfect gas mixture with variable properties are solved in generalized, Eulerian coordinates on a moving grid by making use of an implicit finite volume, Steger-Warming flux vector splitting scheme, and the liquid phase equations are solved in Lagrangian coordinates. Both the details of the numerical algorithm and the finite difference predictions of the combustor flow field during the opening of exhaust and/or intake, and also during fuel vaporization and combustion, are presented.

  19. Computational Performance of a Parallelized Three-Dimensional High-Order Spectral Element Toolbox

    Science.gov (United States)

    Bosshard, Christoph; Bouffanais, Roland; Clémençon, Christian; Deville, Michel O.; Fiétier, Nicolas; Gruber, Ralf; Kehtari, Sohrab; Keller, Vincent; Latt, Jonas

    In this paper, a comprehensive performance review of an MPI-based high-order three-dimensional spectral element method C++ toolbox is presented. The focus is put on the performance evaluation of several aspects with a particular emphasis on the parallel efficiency. The performance evaluation is analyzed with help of a time prediction model based on a parameterization of the application and the hardware resources. A tailor-made CFD computation benchmark case is introduced and used to carry out this review, stressing the particular interest for clusters with up to 8192 cores. Some problems in the parallel implementation have been detected and corrected. The theoretical complexities with respect to the number of elements, to the polynomial degree, and to communication needs are correctly reproduced. It is concluded that this type of code has a nearly perfect speed up on machines with thousands of cores, and is ready to make the step to next-generation petaflop machines.

  20. Three-dimensional multiple reciprocity boundary element method for one-group neutron diffusion eigenvalue computations

    International Nuclear Information System (INIS)

    Itagaki, Masafumi; Sahashi, Naoki.

    1996-01-01

    The multiple reciprocity method (MRM) in conjunction with the boundary element method has been employed to solve one-group eigenvalue problems described by the three-dimensional (3-D) neutron diffusion equation. The domain integral related to the fission source is transformed into a series of boundary-only integrals, with the aid of the higher order fundamental solutions based on the spherical and the modified spherical Bessel functions. Since each degree of the higher order fundamental solutions in the 3-D cases has a singularity of order (1/r), the above series of boundary integrals requires additional terms which do not appear in the 2-D MRM formulation. The critical eigenvalue itself can be also described using only boundary integrals. Test calculations show that Wielandt's spectral shift technique guarantees rapid and stable convergence of 3-D MRM computations. (author)

  1. Three-dimensional viscous-inviscid coupling method for wind turbine computations

    DEFF Research Database (Denmark)

    Ramos García, Néstor; Sørensen, Jens Nørkær; Shen, Wen Zhong

    2016-01-01

    In this paper, a computational model for predicting the aerodynamic behavior of wind turbine wakes and blades subjected to unsteady motions and viscous effects is presented. The model is based on a three-dimensional panel method using a surface distribution of quadrilateral sources and doublets......, which is coupled to a viscous boundary layer solver. Unlike Navier-Stokes codes that need to solve the entire flow domain, the panel method solves the flow around a complex geometry by distributing singularity elements on the body surface, obtaining a faster solution and making this type of codes...... suitable for the design of wind turbines. A free-wake model has been employed to simulate the wake behind a wind turbine by using vortex filaments that carry the vorticity shed by the trailing edge of the blades. Viscous and rotational effects inside the boundary layer are taken into account via...

  2. FLICA-4 (version 1) a computer code for three dimensional thermal analysis of nuclear reactor cores

    International Nuclear Information System (INIS)

    Raymond, P.; Allaire, G.; Boudsocq, G.

    1995-01-01

    FLICA-4 is a thermal-hydraulic computer code developed at the French Energy Atomic Commission (CEA) for three dimensional steady state or transient two phase flow for design and safety thermal analysis of nuclear reactor cores. The two phase flow model of FLICA-4 is based on four balance equations for the fluid which includes: three balance equations for the mixture and a mass balance equation for the less concentrated phase which permits the calculation of non-equilibrium flows as sub cooled boiling and superheated steam. A drift velocity model takes into account the velocity disequilibrium between phases. The thermal behaviour of fuel elements can be computed by a one dimensional heat conduction equation in plane, cylindrical or spherical geometries and coupled to the fluid flow calculation. Convection and diffusion of solution products which are transported either by the liquid or by the gas, can be evaluated by solving specific mass conservation equations. A one dimensional two phase flow model can also be used to compute 1-D flow in pipes, guide tubes, BWR assemblies or RBMK channels. The FLICA-4 computer code uses fast running time steam-water functions. Phasic and saturation physical properties are computed by using bi-cubic spline functions. Polynomial coefficients are tabulated from 0.1 to 22 MPa and 0 to 800 degrees C. Specific modules can be utilised in order to generate the spline coefficients for any other fluid properties

  3. MOSRA-Light; high speed three-dimensional nodal diffusion code for vector computers

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, Keisuke [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    MOSRA-Light is a three-dimensional neutron diffusion calculation code for X-Y-Z geometry. It is based on the 4th order polynomial nodal expansion method (NEM). As the 4th order NEM is not sensitive to mesh sizes, accurate calculation is possible by the use of coarse meshes of about 20 cm. The drastic decrease of number of unknowns in a 3-dimensional problem results in very fast computation. Furthermore, it employs newly developed computation algorithm `boundary separated checkerboard sweep method` appropriate to vector computers. This method is very efficient because the speedup factor by vectorization increases, as a scale of problem becomes larger. Speed-up factor compared to the scalar calculation is from 20 to 40 in the case of PWR core calculation. Considering the both effects by the vectorization and the coarse mesh method, total speedup factor is more than 1000 as compared with conventional scalar code with the finite difference method. MOSRA-Light can be available on most of vector or scalar computers with the UNIX or it`s similar operating systems (e.g. freeware like Linux). Users can easily install it by the help of the conversation style installer. This report contains the general theory of NEM, the fast computation algorithm, benchmark calculation results and detailed information for usage of this code including input data instructions and sample input data. (author)

  4. MOSRA-Light; high speed three-dimensional nodal diffusion code for vector computers

    International Nuclear Information System (INIS)

    Okumura, Keisuke

    1998-10-01

    MOSRA-Light is a three-dimensional neutron diffusion calculation code for X-Y-Z geometry. It is based on the 4th order polynomial nodal expansion method (NEM). As the 4th order NEM is not sensitive to mesh sizes, accurate calculation is possible by the use of coarse meshes of about 20 cm. The drastic decrease of number of unknowns in a 3-dimensional problem results in very fast computation. Furthermore, it employs newly developed computation algorithm 'boundary separated checkerboard sweep method' appropriate to vector computers. This method is very efficient because the speedup factor by vectorization increases, as a scale of problem becomes larger. Speed-up factor compared to the scalar calculation is from 20 to 40 in the case of PWR core calculation. Considering the both effects by the vectorization and the coarse mesh method, total speedup factor is more than 1000 as compared with conventional scalar code with the finite difference method. MOSRA-Light can be available on most of vector or scalar computers with the UNIX or it's similar operating systems (e.g. freeware like Linux). Users can easily install it by the help of the conversation style installer. This report contains the general theory of NEM, the fast computation algorithm, benchmark calculation results and detailed information for usage of this code including input data instructions and sample input data. (author)

  5. Three-Dimensional Optical Coherence Tomography (3D OCT), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Applied Science Innovations, Inc. proposes a new tool of 3D optical coherence tomography (OCT) for cellular level imaging at video frame rates and dramatically...

  6. Identification of muscle necrosis in the mdx mouse model of Duchenne muscular dystrophy using three-dimensional optical coherence tomography

    Science.gov (United States)

    Klyen, Blake R.; Shavlakadze, Thea; Radley-Crabb, Hannah G.; Grounds, Miranda D.; Sampson, David D.

    2011-07-01

    Three-dimensional optical coherence tomography (3D-OCT) was used to image the structure and pathology of skeletal muscle tissue from the treadmill-exercised mdx mouse model of human Duchenne muscular dystrophy. Optical coherence tomography (OCT) images of excised muscle samples were compared with co-registered hematoxylin and eosin-stained and Evans blue dye fluorescence histology. We show, for the first time, structural 3D-OCT images of skeletal muscle dystropathology well correlated with co-located histology. OCT could identify morphological features of interest and necrotic lesions within the muscle tissue samples based on intrinsic optical contrast. These findings demonstrate the utility of 3D-OCT for the evaluation of small-animal skeletal muscle morphology and pathology, particularly for studies of mouse models of muscular dystrophy.

  7. THREE-DIMENSIONAL MODELING TOOLS IN THE PROCESS OF FORMATION OF GRAPHIC COMPETENCE OF THE FUTURE BACHELOR OF COMPUTER SCIENCE

    Directory of Open Access Journals (Sweden)

    Kateryna P. Osadcha

    2017-12-01

    Full Text Available The article is devoted to some aspects of the formation of future bachelor's graphic competence in computer sciences while teaching the fundamentals for working with three-dimensional modelling means. The analysis, classification and systematization of three-dimensional modelling means are given. The aim of research consists in investigating the set of instruments and classification of three-dimensional modelling means and correlation of skills, which are being formed, concerning inquired ones at the labour market in order to use them further in the process of forming graphic competence during training future bachelors in computer sciences. The peculiarities of the process of forming future bachelor's graphic competence in computer sciences by means of revealing, analyzing and systematizing three-dimensional modelling means and types of three-dimensional graphics at present stage of the development of informational technologies are traced a line round. The result of the research is a soft-ware choice in three-dimensional modelling for the process of training future bachelors in computer sciences.

  8. A new method for mapping the three-dimensional atomic distribution within nanoparticles by atom probe tomography (APT).

    Science.gov (United States)

    Kim, Se-Ho; Kang, Phil Woong; Park, O Ok; Seol, Jae-Bok; Ahn, Jae-Pyoung; Lee, Ji Yeong; Choi, Pyuck-Pa

    2018-07-01

    We present a new method of preparing needle-shaped specimens for atom probe tomography from freestanding Pd and C-supported Pt nanoparticles. The method consists of two steps, namely electrophoresis of nanoparticles on a flat Cu substrate followed by electrodeposition of a Ni film acting as an embedding matrix for the nanoparticles. Atom probe specimen preparation can be subsequently carried out by means of focused-ion-beam milling. Using this approach, we have been able to perform correlative atom probe tomography and transmission electron microscopy analyses on both nanoparticle systems. Reliable mass spectra and three-dimensional atom maps could be obtained for Pd nanoparticle specimens. In contrast, atom probe samples prepared from C-supported Pt nanoparticles showed uneven field evaporation and hence artifacts in the reconstructed atom maps. Our developed method is a viable means of mapping the three-dimensional atomic distribution within nanoparticles and is expected to contribute to an improved understanding of the structure-composition-property relationships of various nanoparticle systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. 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.

  10. Overview of 3D-TRACE, a NASA Initiative in Three-Dimensional Tomography of the Aerosol-Cloud Environment

    Science.gov (United States)

    Davis, Anthony; Diner, David; Yanovsky, Igor; Garay, Michael; Xu, Feng; Bal, Guillaume; Schechner, Yoav; Aides, Amit; Qu, Zheng; Emde, Claudia

    2013-04-01

    Remote sensing is a key tool for sorting cloud ensembles by dynamical state, aerosol environments by source region, and establishing causal relationships between aerosol amounts, type, and cloud microphysics-the so-called indirect aerosol climate impacts, and one of the main sources of uncertainty in current climate models. Current satellite imagers use data processing approaches that invariably start with cloud detection/masking to isolate aerosol air-masses from clouds, and then rely on one-dimensional (1D) radiative transfer (RT) to interpret the aerosol and cloud measurements in isolation. Not only does this lead to well-documented biases for the estimates of aerosol radiative forcing and cloud optical depths in current missions, but it is fundamentally inadequate for future missions such as EarthCARE where capturing the complex, three-dimensional (3D) interactions between clouds and aerosols is a primary objective. In order to advance the state of the art, the next generation of satellite information processing systems must incorporate technologies that will enable the treatment of the atmosphere as a fully 3D environment, represented more realistically as a continuum. At one end, there is an optically thin background dominated by aerosols and molecular scattering that is strongly stratified and relatively homogeneous in the horizontal. At the other end, there are optically thick embedded elements, clouds and aerosol plumes, which can be more or less uniform and quasi-planar or else highly 3D with boundaries in all directions; in both cases, strong internal variability may be present. To make this paradigm shift possible, we propose to combine the standard models for satellite signal prediction physically grounded in 1D and 3D RT, both scalar and vector, with technologies adapted from biomedical imaging, digital image processing, and computer vision. This will enable us to demonstrate how the 3D distribution of atmospheric constituents, and their associated

  11. The utility of three-dimensional optical projection tomography in nerve injection injury imaging

    Czech Academy of Sciences Publication Activity Database

    Cvetko, E.; Čapek, Martin; Damjanovska, M.; Reina, M. A.; Eržen, I.; Stopar-Pintarič, T.

    2015-01-01

    Roč. 70, č. 8 (2015), s. 939-947 ISSN 0003-2409 R&D Projects: GA ČR(CZ) GA13-12412S; GA MŠk(CZ) LH13028 Institutional support: RVO:67985823 Keywords : optical projection tomography * 3D nerve visualization * nerve disruption Subject RIV: EA - Cell Biology Impact factor: 3.794, year: 2015

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

    International Nuclear Information System (INIS)

    Chang, L.T.

    1976-05-01

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

  13. Multiobjective optimization framework for landmark measurement error correction in three-dimensional cephalometric tomography.

    Science.gov (United States)

    DeCesare, A; Secanell, M; Lagravère, M O; Carey, J

    2013-01-01

    The purpose of this study is to minimize errors that occur when using a four vs six landmark superimpositioning method in the cranial base to define the co-ordinate system. Cone beam CT volumetric data from ten patients were used for this study. Co-ordinate system transformations were performed. A co-ordinate system was constructed using two planes defined by four anatomical landmarks located by an orthodontist. A second co-ordinate system was constructed using four anatomical landmarks that are corrected using a numerical optimization algorithm for any landmark location operator error using information from six landmarks. The optimization algorithm minimizes the relative distance and angle between the known fixed points in the two images to find the correction. Measurement errors and co-ordinates in all axes were obtained for each co-ordinate system. Significant improvement is observed after using the landmark correction algorithm to position the final co-ordinate system. The errors found in a previous study are significantly reduced. Errors found were between 1 mm and 2 mm. When analysing real patient data, it was found that the 6-point correction algorithm reduced errors between images and increased intrapoint reliability. A novel method of optimizing the overlay of three-dimensional images using a 6-point correction algorithm was introduced and examined. This method demonstrated greater reliability and reproducibility than the previous 4-point correction algorithm.

  14. Three dimensional mapping of Fe dopants in ceria nanocrystals using direct spectroscopic electron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Goris, Bart; Meledina, Maria; Turner, Stuart [EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Zhong, Zhichao [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090 GB Amsterdam (Netherlands); Batenburg, K. Joost [Centrum Wiskunde & Informatica, P.O. Box 94079, 1090 GB Amsterdam (Netherlands); Mathematical Institute, Leiden University, Niels Bohrweg 1, 2333CA Leiden (Netherlands); Bals, Sara [EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2016-12-15

    Electron tomography is a powerful technique for the 3D characterization of the morphology of nanostructures. Nevertheless, resolving the chemical composition of complex nanostructures in 3D remains challenging and the number of studies in which electron energy loss spectroscopy (EELS) is combined with tomography is limited. During the last decade, dedicated reconstruction algorithms have been developed for HAADF-STEM tomography using prior knowledge about the investigated sample. Here, we will use the prior knowledge that the experimental spectrum of each reconstructed voxel is a linear combination of a well-known set of references spectra in a so-called direct spectroscopic tomography technique. Based on a simulation experiment, it is shown that this technique provides superior results in comparison to conventional reconstruction methods for spectroscopic data, especially for spectrum images containing a relatively low signal to noise ratio. Next, this technique is used to investigate the spatial distribution of Fe dopants in Fe:Ceria nanoparticles in 3D. It is shown that the presence of the Fe{sup 2+} dopants is correlated with a reduction of the Ce atoms from Ce{sup 4+} towards Ce{sup 3+}. In addition, it is demonstrated that most of the Fe dopants are located near the voids inside the nanoparticle. - Highlights: • A direct tomographic reconstruction technique is proposed for spectroscopic data. • Spectrum fitting is combined with a tomography reconstruction in a single step. • The technique yields superior results for data with a low signal to noise ratio. • The technique is applied to map Fe dopants in ceria nanoparticles.

  15. Full parallax three-dimensional computer generated hologram with occlusion effect using ray casting technique

    International Nuclear Information System (INIS)

    Zhang, Hao; Tan, Qiaofeng; Jin, Guofan

    2013-01-01

    Holographic display is capable of reconstructing the whole optical wave field of a three-dimensional (3D) scene. It is the only one among all the 3D display techniques that can produce all the depth cues. With the development of computing technology and spatial light modulators, computer generated holograms (CGHs) can now be used to produce dynamic 3D images of synthetic objects. Computation holography becomes highly complicated and demanding when it is employed to produce real 3D images. Here we present a novel algorithm for generating a full parallax 3D CGH with occlusion effect, which is an important property of 3D perception, but has often been neglected in fully computed hologram synthesis. The ray casting technique, which is widely used in computer graphics, is introduced to handle the occlusion issue of CGH computation. Horizontally and vertically distributed rays are projected from each hologram sample to the 3D objects to obtain the complex amplitude distribution. The occlusion issue is handled by performing ray casting calculations to all the hologram samples. The proposed algorithm has no restriction on or approximation to the 3D objects, and hence it can produce reconstructed images with correct shading effect and no visible artifacts. Programmable graphics processing unit (GPU) is used to perform parallel calculation. This is made possible because each hologram sample belongs to an independent operation. To demonstrate the performance of our proposed algorithm, an optical experiment is performed to reconstruct the 3D scene by using a phase-only spatial light modulator. We can easily perceive the accommodation cue by focusing our eyes on different depths of the scene and the motion parallax cue with occlusion effect by moving our eyes around. The experiment result confirms that the CGHs produced by our algorithm can successfully reconstruct 3D images with all the depth cues.

  16. Impact of respiratory movement on the computed tomographic images of small lung tumors in three-dimensional (3D) radiotherapy

    International Nuclear Information System (INIS)

    Shimizu, Shinichi; Shirato, Hiroki; Kagei, Kenji; Nishioka, Takeshi; Bo Xo; Dosaka-Akita, Hirotoshi; Hashimoto, Seiko; Aoyama, Hidefumi; Tsuchiya, Kazuhiko; Miyasaka, Kazuo

    2000-01-01

    Purpose: Three-dimensional (3D) treatment planning has often been performed while patients breathe freely, under the assumption that the computed tomography (CT) images represent the average position of the tumor. We investigated the impact of respiratory movement on the free-breathing CT images of small lung tumors using sequential CT scanning at the same table position. Methods: Using a preparatory free-breathing CT scan, the patient's couch was fixed at the position where each tumor showed its maximum diameter on image. For 16 tumors, over 20 sequential CT images were taken every 2 s, with a 1-s acquisition time occurring during free breathing. For each tumor, the distance between the surface of the CT table and the posterior border of the tumor was measured to determine whether the edge of the tumor was sufficiently included in the planning target volume (PTV) during normal breathing. Results: In the sequential CT scanning, the tumor itself was not visible in the examination slice in 21% (75/357) of cases. There were statistically significant differences between lower lobe tumors (39.4%, 71/180) and upper lobe tumors (0%, 0/89) (p < 0.01) and between lower lobe tumors and middle lobe tumor (8.9%, 4/45) (p < 0.01) in the incidence of the disappearance of the tumor from the image. The mean difference between the maximum and minimum distances between the surface of the CT table and the posterior border of the tumor was 6.4 mm (range 2.1-24.4). Conclusion: Three-dimensional treatment planning for lung carcinoma would significantly underdose many lesions, especially those in the lower lobe. The excess 'safety margin' might call into question any additional benefit of 3D treatment. More work is required to determine how to control respiratory movement

  17. Three-dimensional image acquisition and reconstruction system on a mobile device based on computer-generated integral imaging.

    Science.gov (United States)

    Erdenebat, Munkh-Uchral; Kim, Byeong-Jun; Piao, Yan-Ling; Park, Seo-Yeon; Kwon, Ki-Chul; Piao, Mei-Lan; Yoo, Kwan-Hee; Kim, Nam

    2017-10-01

    A mobile three-dimensional image acquisition and reconstruction system using a computer-generated integral imaging technique is proposed. A depth camera connected to the mobile device acquires the color and depth data of a real object simultaneously, and an elemental image array is generated based on the original three-dimensional information for the object, with lens array specifications input into the mobile device. The three-dimensional visualization of the real object is reconstructed on the mobile display through optical or digital reconstruction methods. The proposed system is implemented successfully and the experimental results certify that the system is an effective and interesting method of displaying real three-dimensional content on a mobile device.

  18. Micro-tomography based Geometry Modeling of Three-Dimensional Braided Composites

    Science.gov (United States)

    Fang, Guodong; Chen, Chenghua; Yuan, Shenggang; Meng, Songhe; Liang, Jun

    2018-06-01

    A tracking and recognizing algorithm is proposed to automatically generate irregular cross-sections and central path of braid yarn within the 3D braided composites by using sets of high resolution tomography images. Only the initial cross-sections of braid yarns in a tomography image after treatment are required to be calibrated manually as searching cross-section template. The virtual geometry of 3D braided composites including some detailed geometry information, such as the braid yarn squeezing deformation, braid yarn distortion and braid yarn path deviation etc., can be reconstructed. The reconstructed geometry model can reflect the change of braid configurations during solidification process. The geometry configurations and mechanical properties of the braided composites are analyzed by using the reconstructed geometry model.

  19. Three-dimensional optoacoustic tomography using a conventional ultrasound linear detector array: whole-body tomographic system for small animals.

    Science.gov (United States)

    Gateau, Jerome; Caballero, Miguel Angel Araque; Dima, Alexander; Ntziachristos, Vasilis

    2013-01-01

    Optoacoustic imaging relies on the detection of ultrasonic waves induced by laser pulse excitations to map optical absorption in biological tissue. A tomographic geometry employing a conventional ultrasound linear detector array for volumetric optoacoustic imaging is reported. The geometry is based on a translate-rotate scanning motion of the detector array, and capitalizes on the geometrical characteristics of the transducer assembly to provide a large solid angular detection aperture. A system for three-dimensional whole-body optoacoustic tomography of small animals is implemented. The detection geometry was tested using a 128-element linear array (5.0∕7.0 MHz, Acuson L7, Siemens), moved by steps with a rotation∕translation stage assembly. Translation and rotation range of 13.5 mm and 180°, respectively, were implemented. Optoacoustic emissions were induced in tissue-mimicking phantoms and ex vivo mice using a pulsed laser operating in the near-IR spectral range at 760 nm. Volumetric images were formed using a filtered backprojection algorithm. The resolution of the optoacoustic tomography system was measured to be better than 130 μm in-plane and 330 μm in elevation (full width half maximum), and to be homogenous along a 15 mm diameter cross section due to the translate-rotate scanning geometry. Whole-body volumetric optoacoustic images of mice were performed ex vivo, and imaged organs and blood vessels through the intact abdominal and head regions were correlated to the mouse anatomy. Overall, the feasibility of three-dimensional and high-resolution whole-body optoacoustic imaging of small animal using a conventional linear array was demonstrated. Furthermore, the scanning geometry may be used for other linear arrays and is therefore expected to be of great interest for optoacoustic tomography at macroscopic and mesoscopic scale. Specifically, conventional detector arrays with higher central frequencies may be investigated.

  20. About some generalization of calculation algorithm of three-dimensional images in the emission tomography

    International Nuclear Information System (INIS)

    Koblik, Yu.N.; Khugaev, A.V.; Mktchyan, G.A; Yuldashev, B.S.; Iloannou, P.; Dimovasili, E

    2002-01-01

    The aim of the work is the generalization of algorithm of processing of images of the objects in the emission tomography for case of arbitrarily directed cuts. In this work the problem of description of the mathematical law of lines of the such cuts in idealized event and with taking into account the parameters of cells in the working cavity of tomograph had been solved

  1. Three-dimensional densitometry imaging of diatom cells using STIM tomography

    International Nuclear Information System (INIS)

    Habchi, C.; Nguyen, D.T.; Deves, G.; Incerti, S.; Lemelle, L.; Van Vang, P. Le; Moretto, Ph.; Ortega, R.; Seznec, H.; Sakellariou, A.; Sergeant, C.; Simionovici, A.; Ynsa, M.D.; Gontier, E.; Heiss, M.; Pouthier, T.; Boudou, A.; Rebillat, F.

    2006-01-01

    Scanning transmission ion microscopy tomography (STIM-T) was carried out on diatom cells with the aim of displaying their 3D structure and performing density measurements on their silica skeleton. Two software packages were compared for data reduction: TomoRebuild, based on a simple filtered backprojection algorithm, and DISRA, an iterative program. Silicon carbide microfibres of known density were also analysed as reference specimens. Similar results were obtained with both algorithms, demonstrating the ability of STIM-T to provide density measurements at the cell level without requiring any standard calibration samples. This unique feature stresses the interest of STIM-T to accurately normalise X ray emission micro-tomography data from synchrotron radiation (SXRF: synchrotron radiation X-ray fluorescence) or ion beam sources (PIXE: particle induced X-ray emission). Possible enhancements of the DISRA code are discussed in order to facilitate its use for the reconstruction of future PIXE/STIM tomography data. A 'nanoprobe' coupled to a Singletron[reg] accelerator, allowing a spatial resolution of a few tens of nanometers, is going to be built in the coming months at the Centre d'Etudes Nucleaires de Bordeaux Gradignan (CENBG). This new facility will bring promising applications in imaging and analysis at the sub-cellular level

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... to reduce the risk of an allergic reaction. These medications must be taken 12 hours prior to ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... to reduce the risk of an allergic reaction. These medications must be taken 12 hours prior to ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ...

  4. A new method of three-dimensional computer assisted reconstruction of the developing biliary tract.

    Science.gov (United States)

    Prudhomme, M; Gaubert-Cristol, R; Jaeger, M; De Reffye, P; Godlewski, G

    1999-01-01

    A three-dimensional (3-D) computer assisted reconstruction of the biliary tract was performed in human and rat embryos at Carnegie stage 23 to describe and compare the biliary structures and to point out the anatomic relations between the structures of the hepatic pedicle. Light micrograph images from consecutive serial sagittal sections (diameter 7 mm) of one human and 16 rat embryos were directly digitalized with a CCD camera. The serial views were aligned automatically by software. The data were analysed following segmentation and thresholding, allowing automatic reconstruction. The main bile ducts ascended in the mesoderm of the hepatoduodenal ligament. The extrahepatic bile ducts: common bile duct (CD), cystic duct and gallbladder in the human, formed a compound system which could not be shown so clearly in histologic sections. The hepato-pancreatic ampulla was studied as visualised through the duodenum. The course of the CD was like a chicane. The gallbladder diameter and length were similar to those of the CD. Computer-assisted reconstruction permitted easy acquisition of the data by direct examination of the sections through the microscope. This method showed the relationships between the different structures of the hepatic pedicle and allowed estimation of the volume of the bile duct. These findings were not obvious in two-dimensional (2-D) views from histologic sections. Each embryonic stage could be rebuilt in 3-D, which could introduce the time as a fourth dimension, fundamental for the study of organogenesis.

  5. Three-dimensional integration of nanotechnologies for computing and data storage on a single chip

    Science.gov (United States)

    Shulaker, Max M.; Hills, Gage; Park, Rebecca S.; Howe, Roger T.; Saraswat, Krishna; Wong, H.-S. Philip; Mitra, Subhasish

    2017-07-01

    The computing demands of future data-intensive applications will greatly exceed the capabilities of current electronics, and are unlikely to be met by isolated improvements in transistors, data storage technologies or integrated circuit architectures alone. Instead, transformative nanosystems, which use new nanotechnologies to simultaneously realize improved devices and new integrated circuit architectures, are required. Here we present a prototype of such a transformative nanosystem. It consists of more than one million resistive random-access memory cells and more than two million carbon-nanotube field-effect transistors—promising new nanotechnologies for use in energy-efficient digital logic circuits and for dense data storage—fabricated on vertically stacked layers in a single chip. Unlike conventional integrated circuit architectures, the layered fabrication realizes a three-dimensional integrated circuit architecture with fine-grained and dense vertical connectivity between layers of computing, data storage, and input and output (in this instance, sensing). As a result, our nanosystem can capture massive amounts of data every second, store it directly on-chip, perform in situ processing of the captured data, and produce ‘highly processed’ information. As a working prototype, our nanosystem senses and classifies ambient gases. Furthermore, because the layers are fabricated on top of silicon logic circuitry, our nanosystem is compatible with existing infrastructure for silicon-based technologies. Such complex nano-electronic systems will be essential for future high-performance and highly energy-efficient electronic systems.

  6. Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Don; Park, Chang Seo [Dept. of Dental Radiology, College of Dentistry, Yensei University, Seoul (Korea, Republic of); Yoo, Sun Kook; Lee, Kyoung Sang [Dept. of Medical Engineering, College of Medicine, Yensei University, Seoul (Korea, Republic of)

    1998-08-15

    In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of

  7. Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

    International Nuclear Information System (INIS)

    Kim, Hyun Don; Park, Chang Seo; Yoo, Sun Kook; Lee, Kyoung Sang

    1998-01-01

    In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of

  8. Three-Dimensional Segmentation of the Tumor in Computed Tomographic Images of Neuroblastoma

    OpenAIRE

    Deglint, Hanford J.; Rangayyan, Rangaraj M.; Ayres, Fábio J.; Boag, Graham S.; Zuffo, Marcelo K.

    2006-01-01

    Segmentation of the tumor in neuroblastoma is complicated by the fact that the mass is almost always heterogeneous in nature; furthermore, viable tumor, necrosis, and normal tissue are often intermixed. Tumor definition and diagnosis require the analysis of the spatial distribution and Hounsfield unit (HU) values of voxels in computed tomography (CT) images, coupled with a knowledge of normal anatomy. Segmentation and analysis of the tissue composition of the tumor can assist in quantitative ...

  9. Three-dimensional crustal model of the Moravo-Silesian region obtained by seismic tomography

    Czech Academy of Sciences Publication Activity Database

    Růžek, Bohuslav; Holub, Karel; Rušajová, Jana

    2011-01-01

    Roč. 55, č. 1 (2011), s. 87-107 ISSN 0039-3169 R&D Projects: GA AV ČR IAA200120701; GA MŽP SB/630/3/02; GA ČR GA205/03/0999 Institutional research plan: CEZ:AV0Z30120515; CEZ:AV0Z30860518 Keywords : seismic tomography * 3D seismic velocity model * Moravo-Silesian region Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.700, year: 2011

  10. Three-Dimensional Computer Simulation as an Important Competence Based Aspect of a Modern Mining Professional

    Science.gov (United States)

    Aksenova, Olesya; Pachkina, Anna

    2017-11-01

    The article deals with the problem of necessity of educational process transformation to meet the requirements of modern miming industry; cooperative developing of new educational programs and implementation of educational process taking into account modern manufacturability. The paper proves the idea of introduction into mining professionals learning process studying of three-dimensional models of surface technological complex, ore reserves and underground digging complex as well as creating these models in different graphic editors and working with the information analysis model obtained on the basis of these three-dimensional models. The technological process of manless coal mining at the premises of the mine Polysaevskaya controlled by the information analysis models built on the basis of three-dimensional models of individual objects and technological process as a whole, and at the same time requiring the staff able to use the programs of three-dimensional positioning in the miners and equipment global frame of reference is covered.

  11. A computational model to generate simulated three-dimensional breast masses

    Energy Technology Data Exchange (ETDEWEB)

    Sisternes, Luis de; Brankov, Jovan G.; Zysk, Adam M.; Wernick, Miles N., E-mail: wernick@iit.edu [Medical Imaging Research Center, Department of Electrical and Computer Engineering, Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Schmidt, Robert A. [Kurt Rossmann Laboratories for Radiologic Image Research, Department of Radiology, The University of Chicago, Chicago, Illinois 60637 (United States); Nishikawa, Robert M. [Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)

    2015-02-15

    Purpose: To develop algorithms for creating realistic three-dimensional (3D) simulated breast masses and embedding them within actual clinical mammograms. The proposed techniques yield high-resolution simulated breast masses having randomized shapes, with user-defined mass type, size, location, and shape characteristics. Methods: The authors describe a method of producing 3D digital simulations of breast masses and a technique for embedding these simulated masses within actual digitized mammograms. Simulated 3D breast masses were generated by using a modified stochastic Gaussian random sphere model to generate a central tumor mass, and an iterative fractal branching algorithm to add complex spicule structures. The simulated masses were embedded within actual digitized mammograms. The authors evaluated the realism of the resulting hybrid phantoms by generating corresponding left- and right-breast image pairs, consisting of one breast image containing a real mass, and the opposite breast image of the same patient containing a similar simulated mass. The authors then used computer-aided diagnosis (CAD) methods and expert radiologist readers to determine whether significant differences can be observed between the real and hybrid images. Results: The authors found no statistically significant difference between the CAD features obtained from the real and simulated images of masses with either spiculated or nonspiculated margins. Likewise, the authors found that expert human readers performed very poorly in discriminating their hybrid images from real mammograms. Conclusions: The authors’ proposed method permits the realistic simulation of 3D breast masses having user-defined characteristics, enabling the creation of a large set of hybrid breast images containing a well-characterized mass, embedded within real breast background. The computational nature of the model makes it suitable for detectability studies, evaluation of computer aided diagnosis algorithms, and

  12. A computational model to generate simulated three-dimensional breast masses

    International Nuclear Information System (INIS)

    Sisternes, Luis de; Brankov, Jovan G.; Zysk, Adam M.; Wernick, Miles N.; Schmidt, Robert A.; Nishikawa, Robert M.

    2015-01-01

    Purpose: To develop algorithms for creating realistic three-dimensional (3D) simulated breast masses and embedding them within actual clinical mammograms. The proposed techniques yield high-resolution simulated breast masses having randomized shapes, with user-defined mass type, size, location, and shape characteristics. Methods: The authors describe a method of producing 3D digital simulations of breast masses and a technique for embedding these simulated masses within actual digitized mammograms. Simulated 3D breast masses were generated by using a modified stochastic Gaussian random sphere model to generate a central tumor mass, and an iterative fractal branching algorithm to add complex spicule structures. The simulated masses were embedded within actual digitized mammograms. The authors evaluated the realism of the resulting hybrid phantoms by generating corresponding left- and right-breast image pairs, consisting of one breast image containing a real mass, and the opposite breast image of the same patient containing a similar simulated mass. The authors then used computer-aided diagnosis (CAD) methods and expert radiologist readers to determine whether significant differences can be observed between the real and hybrid images. Results: The authors found no statistically significant difference between the CAD features obtained from the real and simulated images of masses with either spiculated or nonspiculated margins. Likewise, the authors found that expert human readers performed very poorly in discriminating their hybrid images from real mammograms. Conclusions: The authors’ proposed method permits the realistic simulation of 3D breast masses having user-defined characteristics, enabling the creation of a large set of hybrid breast images containing a well-characterized mass, embedded within real breast background. The computational nature of the model makes it suitable for detectability studies, evaluation of computer aided diagnosis algorithms, and

  13. Three-Dimensional Computer-Aided Detection of Microcalcification Clusters in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Ji-wook Jeong

    2016-01-01

    Full Text Available We propose computer-aided detection (CADe algorithm for microcalcification (MC clusters in reconstructed digital breast tomosynthesis (DBT images. The algorithm consists of prescreening, MC detection, clustering, and false-positive (FP reduction steps. The DBT images containing the MC-like objects were enhanced by a multiscale Hessian-based three-dimensional (3D objectness response function and a connected-component segmentation method was applied to extract the cluster seed objects as potential clustering centers of MCs. Secondly, a signal-to-noise ratio (SNR enhanced image was also generated to detect the individual MC candidates and prescreen the MC-like objects. Each cluster seed candidate was prescreened by counting neighboring individual MC candidates nearby the cluster seed object according to several microcalcification clustering criteria. As a second step, we introduced bounding boxes for the accepted seed candidate, clustered all the overlapping cubes, and examined. After the FP reduction step, the average number of FPs per case was estimated to be 2.47 per DBT volume with a sensitivity of 83.3%.

  14. A Computational/Experimental Platform for Investigating Three-Dimensional Puzzle Solving of Comminuted Articular Fractures

    Science.gov (United States)

    Thomas, Thaddeus P.; Anderson, Donald D.; Willis, Andrew R.; Liu, Pengcheng; Frank, Matthew C.; Marsh, J. Lawrence; Brown, Thomas D.

    2011-01-01

    Reconstructing highly comminuted articular fractures poses a difficult surgical challenge, akin to solving a complicated three-dimensional (3D) puzzle. Pre-operative planning using CT is critically important, given the desirability of less invasive surgical approaches. The goal of this work is to advance 3D puzzle solving methods toward use as a pre-operative tool for reconstructing these complex fractures. Methodology for generating typical fragmentation/dispersal patterns was developed. Five identical replicas of human distal tibia anatomy, were machined from blocks of high-density polyetherurethane foam (bone fragmentation surrogate), and were fractured using an instrumented drop tower. Pre- and post-fracture geometries were obtained using laser scans and CT. A semi-automatic virtual reconstruction computer program aligned fragment native (non-fracture) surfaces to a pre-fracture template. The tibias were precisely reconstructed with alignment accuracies ranging from 0.03-0.4mm. This novel technology has potential to significantly enhance surgical techniques for reconstructing comminuted intra-articular fractures, as illustrated for a representative clinical case. PMID:20924863

  15. Three-dimensional time-dependent computer modeling of the electrothermal atomizers for analytical spectrometry

    Science.gov (United States)

    Tsivilskiy, I. V.; Nagulin, K. Yu.; Gilmutdinov, A. Kh.

    2016-02-01

    A full three-dimensional nonstationary numerical model of graphite electrothermal atomizers of various types is developed. The model is based on solution of a heat equation within solid walls of the atomizer with a radiative heat transfer and numerical solution of a full set of Navier-Stokes equations with an energy equation for a gas. Governing equations for the behavior of a discrete phase, i.e., atomic particles suspended in a gas (including gas-phase processes of evaporation and condensation), are derived from the formal equations molecular kinetics by numerical solution of the Hertz-Langmuir equation. The following atomizers test the model: a Varian standard heated electrothermal vaporizer (ETV), a Perkin Elmer standard THGA transversely heated graphite tube with integrated platform (THGA), and the original double-stage tube-helix atomizer (DSTHA). The experimental verification of computer calculations is carried out by a method of shadow spectral visualization of the spatial distributions of atomic and molecular vapors in an analytical space of an atomizer.

  16. A three-dimensional computer code for the nonlinear dynamic response of an HTGR core

    International Nuclear Information System (INIS)

    Subudhi, M.; Lasker, L.; Koplik, B.; Curreri, J.; Goradia, H.

    1979-01-01

    A three-dimensional dynamic code has been developed to determine the nonlinear response of an HTGR core. The HTGR core consists of several thousands of hexagonal core blocks. These are arranged in layers stacked together. Each layer contains many core blocks surrounded on their outer periphery by reflector blocks. The entire assembly is contained within a prestressed concrete reactor vessel. Gaps exist between adjacent blocks in any horizontal plane. Each core block in a given layer is connected to the blocks directly above and below it via three dowell pins. The present analytical study is directed towards an investigation of the nonlinear response of the reactor core blocks in the event of a seismic occurrence. The computer code is developed for a specific mathematical model which represents a vertical arrangement of layers of blocks. This comprises a 'block module' of core elements which would be obtained by cutting a cylindrical portion consisting of seven fuel blocks per layer. It is anticipated that a number of such modules properly arranged could represent the entire core. Hence, the predicted response of this module would exhibit the response characteristics of the core. (orig.)

  17. Affective three-dimensional brain-computer interface created using a prism array-based display

    Science.gov (United States)

    Mun, Sungchul; Park, Min-Chul

    2014-12-01

    To avoid the vergence-accommodation mismatch and provide a strong sense of presence to users, we applied a prism array-based display when presenting three-dimensional (3-D) objects. Emotional pictures were used as visual stimuli to increase the signal-to-noise ratios of steady-state visually evoked potentials (SSVEPs) because involuntarily motivated selective attention by affective mechanisms can enhance SSVEP amplitudes, thus producing increased interaction efficiency. Ten male and nine female participants voluntarily participated in our experiments. Participants were asked to control objects under three viewing conditions: two-dimension (2-D), stereoscopic 3-D, and prism. The participants performed each condition in a counter-balanced order. One-way repeated measures analysis of variance showed significant increases in the positive predictive values in the prism condition compared to the 2-D and 3-D conditions. Participants' subjective ratings of realness and engagement were also significantly greater in the prism condition than in the 2-D and 3-D conditions, while the ratings for visual fatigue were significantly reduced in the prism condition than in the 3-D condition. The proposed methods are expected to enhance the sense of reality in 3-D space without causing critical visual fatigue. In addition, people who are especially susceptible to stereoscopic 3-D may be able to use the affective brain-computer interface.

  18. Three-dimensional computer code for the nonlinear dynamic response of an HTGR core

    International Nuclear Information System (INIS)

    Subudhi, M.; Lasker, L.; Koplik, B.; Curreri, J.; Goradia, H.

    1979-01-01

    A three-dimensional dynamic code has been developed to determine the nonlinear response of an HTGR core. The HTGR core consists of several thousands of hexagonal core blocks. These are arranged inlayers stacked together. Each layer contains many core blocks surrounded on their outer periphery by reflector blocks. The entire assembly is contained within a prestressed concrete reactor vessel. Gaps exist between adjacent blocks in any horizontal plane. Each core block in a given layer is connected to the blocks directly above and below it via three dowell pins. The present analystical study is directed towards an invesstigation of the nonlinear response of the reactor core blocks in the event of a seismic occurrence. The computer code is developed for a specific mathemtical model which represents a vertical arrangement of layers of blocks. This comprises a block module of core elements which would be obtained by cutting a cylindrical portion consisting of seven fuel blocks per layer. It is anticipated that a number of such modules properly arranged could represent the entire core. Hence, the predicted response of this module would exhibit the response characteristics of the core

  19. On fully three-dimensional resistive wall mode and feedback stabilization computations

    International Nuclear Information System (INIS)

    Strumberger, E.; Merkel, P.; Sempf, M.; Guenter, S.

    2008-01-01

    Resistive walls, located close to the plasma boundary, reduce the growth rates of external kink modes to resistive time scales. For such slowly growing resistive wall modes, the stabilization by an active feedback system becomes feasible. The fully three-dimensional stability code STARWALL, and the feedback optimization code OPTIM have been developed [P. Merkel and M. Sempf, 21st IAEA Fusion Energy Conference 2006, Chengdu, China (International Atomic Energy Agency, Vienna, 2006, paper TH/P3-8] to compute the growth rates of resistive wall modes in the presence of nonaxisymmetric, multiply connected wall structures and to model the active feedback stabilization of these modes. In order to demonstrate the capabilities of the codes and to study the effect of the toroidal mode coupling caused by multiply connected wall structures, the codes are applied to test equilibria using the resistive wall structures currently under debate for ITER [M. Shimada et al., Nucl. Fusion 47, S1 (2007)] and ASDEX Upgrade [W. Koeppendoerfer et al., Proceedings of the 16th Symposium on Fusion Technology, London, 1990 (Elsevier, Amsterdam, 1991), Vol. 1, p. 208

  20. Automatic classification of retinal three-dimensional optical coherence tomography images using principal component analysis network with composite kernels.

    Science.gov (United States)

    Fang, Leyuan; Wang, Chong; Li, Shutao; Yan, Jun; Chen, Xiangdong; Rabbani, Hossein

    2017-11-01

    We present an automatic method, termed as the principal component analysis network with composite kernel (PCANet-CK), for the classification of three-dimensional (3-D) retinal optical coherence tomography (OCT) images. Specifically, the proposed PCANet-CK method first utilizes the PCANet to automatically learn features from each B-scan of the 3-D retinal OCT images. Then, multiple kernels are separately applied to a set of very important features of the B-scans and these kernels are fused together, which can jointly exploit the correlations among features of the 3-D OCT images. Finally, the fused (composite) kernel is incorporated into an extreme learning machine for the OCT image classification. We tested our proposed algorithm on two real 3-D spectral domain OCT (SD-OCT) datasets (of normal subjects and subjects with the macular edema and age-related macular degeneration), which demonstrated its effectiveness. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  1. Real-time three-dimensional temperature mapping in photothermal therapy with optoacoustic tomography

    Science.gov (United States)

    Oyaga Landa, Francisco Javier; Deán-Ben, Xosé Luís.; Sroka, Ronald; Razansky, Daniel

    2017-07-01

    Ablation and photothermal therapy are widely employed medical protocols where the selective destruction of tissue is a necessity as in cancerous tissue removal or vascular and brain abnormalities. Tissue denaturation takes place when the temperature reaches a threshold value while the time of exposure determines the lesion size. Therefore, the spatio-temporal distribution of temperature plays a crucial role in the outcome of these clinical interventions. We demonstrate fast volumetric temperature mapping with optoacoustic tomography based on real-time optoacoustic readings from the treated region. The performance of the method was investigated in tissue-mimicking phantom experiments. The new ability to non-invasively measure temperature volumetrically in an entire treated region with high spatial and temporal resolutions holds potential for improving safety and efficacy of thermal ablation and to advance the general applicability of laser-based therapy.

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

    Science.gov (United States)

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

    1999-04-01

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

  3. Lung nodule detection performance in five observers on computed tomography (CT) with adaptive iterative dose reduction using three-dimensional processing (AIDR 3D) in a Japanese multicenter study: Comparison between ultra-low-dose CT and low-dose CT by receiver-operating characteristic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nagatani, Yukihiro, E-mail: yatsushi@belle.shiga-med.ac.jp [Department of Radiology, Shiga University of Medical Science, Otsu 520-2192, Shiga (Japan); Takahashi, Masashi; Murata, Kiyoshi [Department of Radiology, Shiga University of Medical Science, Otsu 520-2192, Shiga (Japan); Ikeda, Mitsuru [Department of Radiological and Medical Laboratory Science, Nagoya University Graduate School of Medicine, Nagoya 461-8673, Aichi (Japan); Yamashiro, Tsuneo [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan); Miyara, Tetsuhiro [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan); Department of Radiology, Okinawa Prefectural Yaeyama Hospital, Ishigaki 907-0022, Okinawa (Japan); Koyama, Hisanobu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Hyogo (Japan); Koyama, Mitsuhiro [Department of Radiology, Osaka Medical College, Takatsuki 569-8686, Osaka (Japan); Sato, Yukihisa [Department of Radiology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka (Japan); Department of Radiology, Osaka Medical Center of Cancer and Cardiovascular Diseases, Osaka 537-8511, Osaka (Japan); Moriya, Hiroshi [Department of Radiology, Ohara General Hospital, Fukushima 960-8611 (Japan); Noma, Satoshi [Department of Radiology, Tenri Hospital, Tenri 632-8552, Nara (Japan); Tomiyama, Noriyuki [Department of Radiology, Osaka University Graduate School of Medicine, Suita 565-0871, Osaka (Japan); Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, Kobe 650-0017, Hyogo (Japan); Murayama, Sadayuki [Department of Radiology, Graduate School of Medical Science, University of the Ryukyus, Nishihara 903-0215, Okinawa (Japan)

    2015-07-15

    Highlights: • Using AIDR 3D, ULDCT showed comparable LND of solid nodules to LDCT. • Using AIDR 3D, LND of smaller GGN in ULDCT was inferior to that in LDCT. • Effective dose in ULDCT was about only twice of that in chest X-ray. • BMI values in study population were mostly in the normal range body habitus. - Abstract: Purpose: To compare lung nodule detection performance (LNDP) in computed tomography (CT) with adaptive iterative dose reduction using three dimensional processing (AIDR3D) between ultra-low dose CT (ULDCT) and low dose CT (LDCT). Materials and methods: This was part of the Area-detector Computed Tomography for the Investigation of Thoracic Diseases (ACTIve) Study, a multicenter research project being conducted in Japan. Institutional Review Board approved this study and informed consent was obtained. Eighty-three subjects (body mass index, 23.3 ± 3.2) underwent chest CT at 6 institutions using identical scanners and protocols. In a single visit, each subject was scanned using different tube currents: 240, 120 and 20 mA (3.52, 1.74 and 0.29 mSv, respectively). Axial CT images with 2-mm thickness/increment were reconstructed using AIDR3D. Standard of reference (SOR) was determined based on CT images at 240 mA by consensus reading of 2 board-certificated radiologists as to the presence of lung nodules with the longest diameter (LD) of more than 3 mm. Another 5 radiologists independently assessed and recorded presence/absence of lung nodules and their locations by continuously-distributed rating in CT images at 20 mA (ULDCT) and 120 mA (LDCT). Receiver-operating characteristic (ROC) analysis was used to evaluate LNDP of both methods in total and also in subgroups classified by LD (>4, 6 and 8 mm) and nodular characteristics (solid and ground glass nodules). Results: For SOR, 161 solid and 60 ground glass nodules were identified. No significant difference in LNDP for entire solid nodules was demonstrated between both methods, as area under ROC

  4. Three-dimensional display by computer graphics method of hepatocellular carcinoma using seen with the hepatic arteriogram

    International Nuclear Information System (INIS)

    Itsubo, Mariko; Kameda, Haruo; Suzuki, Naoki; Okamura, Tetsuo

    1989-01-01

    The method of three-dimensional display of hepatocellular carcinoma using conventional hepatic arteriogram by computer graphics method was newly exploited and applied in clinical use. Three-dimensional models were reconstructed from contour lines of tumors demonstrated as hypervascular lesions by hepatic arteriography. Although objects were limited by angiographic images in which tumors need to be demonstrated as nodules with hypervascularity, this method of three-dimensional display was not worse on accuracy than that using computed tomographic images. According to this method property of the tumor expressed by vascularity was demonstrated clear and in addition volume of the tumor was calculated easily. When the tumor arose in necrotic changes in which demonstrated as a vascular lesion by hepatic arteriography with reduction of size in usual by conservative treatment such as transcathter arterial embolization therapy, this three-dimensional display was able to demonstrate such changes clear. This preliminary study demonstrates the feasibility and clinical usefulness of three-dimensional display of hepatocellular carcinoma using hepatic arteriogram by computer graphics method. (author)

  5. Three-dimensional analysis and classification of arteries in the skin and subcutaneous adipofascial tissue by computer graphics imaging.

    Science.gov (United States)

    Nakajima, H; Minabe, T; Imanishi, N

    1998-09-01

    To develop new types of surgical flaps that utilize portions of the skin and subcutaneous tissue (e.g., a thin flap or an adipofascial flap), three-dimensional investigation of the vasculature in the skin and subcutaneous tissue has been anticipated. In the present study, total-body arterial injection and three-dimensional imaging of the arteries by computer graphics were performed. The full-thickness skin and subcutaneous adipofascial tissue samples, which were obtained from fresh human cadavers injected with radio-opaque medium, were divided into three distinct layers. Angiograms of each layer were introduced into a personal computer to construct three-dimensional images. On a computer monitor, each artery was shown color-coded according to the three portions: the deep adipofascial layer, superficial adipofascial layer, and dermis. Three-dimensional computerized images of each artery in the skin and subcutaneous tissue revealed the components of each vascular plexus and permitted their classification into six types. The distribution of types in the body correlated with the tissue mobility of each area. Clinically, appreciation of the three-dimensional structure of the arteries allowed the development of several new kinds of flaps.

  6. Dynamic time-dependent analysis and static three-dimensional imaging procedures for computer-assisted CNS studies

    International Nuclear Information System (INIS)

    Budinger, T.F.; DeLand, F.H.; Duggan, H.E.; Bouz, J.J.; Hoop, B. Jr.; McLaughlin, W.T.; Weber, P.M.

    1975-01-01

    Two-dimensional computer image-processing techniques have not proved to be of importance in diagnostic nuclear medicine primarily because the radionuclide distribution represents a three-dimensional problem. More recent developments in three-dimensional reconstruction from multiple views or multiple detectors promise to overcome the major limitations in previous work with digital computers. These techniques are now in clinical use for static imaging; however, speed limitations have prevented application to dynamic imaging. The future development of these methods will require innovations in patient positioning and multiple-view devices for either single-gamma or positron annihilation detection

  7. TEMPEST: A three-dimensional time-dependent computer program for hydrothermal analysis: Volume 1, Numerical methods and input instructions

    International Nuclear Information System (INIS)

    Trent, D.S.; Eyler, L.L.; Budden, M.J.

    1983-09-01

    This document describes the numerical methods, current capabilities, and the use of the TEMPEST (Version L, MOD 2) computer program. TEMPEST is a transient, three-dimensional, hydrothermal computer program that is designed to analyze a broad range of coupled fluid dynamic and heat transfer systems of particular interest to the Fast Breeder Reactor thermal-hydraulic design community. The full three-dimensional, time-dependent equations of motion, continuity, and heat transport are solved for either laminar or turbulent fluid flow, including heat diffusion and generation in both solid and liquid materials. 10 refs., 22 figs., 2 tabs

  8. Three-dimensional, Computer-tomographic Analysis of Membrane Proteins (TrkA, caveolin, clathrin) in PC12 Cells

    International Nuclear Information System (INIS)

    Nishida, Tomoki; Arii, Tatsuo; Takaoka, Akio; Yoshimura, Ryoichi; Endo, Yasuhisa

    2007-01-01

    Signaling of nerve growth factor (NGF) and its receptor (TrkA) promotes neuronal differentiation, synapse formation and survival. It has been known that the complex of NGF and TrkA is internalized into the cytoplasm and transported for further signal transduction, but the ultrastructural information of this process is virtually unknown. In order to clarify the relationship between the internalization of TrkA and the membrane-associated proteins (caveolin and clathrin), the localization and three-dimensional structures of those proteins were examined with computer tomography of high voltage electron microscopy in PC12 cells. TrkA immunoreactivity was found only at definite areas in the plasma membrane, as ring and cluster structures. Its 3D image indicated that those cluster structures contained small pits, which did not appear to be typical caveolae in size and shape. 3D images of clathrin and caveolin-1 immunoreactivities indicated that the formation of those small pits was associated with clathrin, but not with caveolin-1. Caveolin-1 immunoreactivity was found as a mesh-like structure just beneath the plasma membrane. These results suggest that clathrin rather than caveolin is mainly involved in the process of TrkA internalization, at least in differentiated PC12 cells

  9. Generalization of Spatial Channel Theory to Three-Dimensional x-y-z Transport Computations

    International Nuclear Information System (INIS)

    Abu-Shumays, I. K.; Hunter, M. A.; Martz, R. L.; Risner, J. M.

    2002-01-01

    Spatial channel theory, initially introduced in 1977 by M. L. Williams and colleagues at ORNL, is a powerful tool for shield design optimization. It focuses on so called ''contributon'' flux and current of particles (a fraction of the total of neutrons, photons, etc.) which contribute directly or through their progeny to a pre-specified response, such as a detector reading, dose rate, reaction rate, etc., at certain locations of interest. Particles that do not contribute directly or indirectly to the pre-specified response, such as particles that are absorbed or leak out, are ignored. Contributon fluxes and currents are computed based on combined forward and adjoint transport solutions. The initial concepts were considerably improved by Abu-Shumays, Selva, and Shure by introducing steam functions and response flow functions. Plots of such functions provide both qualitative and quantitative information on dominant particle flow paths and identify locations within a shield configuration that are important in contributing to the response of interest. Previous work was restricted to two dimensional (2-D) x-y rectangular and r-z cylindrical geometries. This paper generalizes previous work to three-dimensional x-y-z geometry, since it is now practical to solve realistic 3-D problems with multidimensional transport programs. As in previous work, new analytic expressions are provided for folding spherical harmonics representations of forward and adjoint transport flux solutions. As a result, the main integrals involve in spatial channel theory are computed exactly and more efficiently than by numerical quadrature. The analogy with incompressible fluid flow is also applied to obtain visual qualitative and quantitative measures of important streaming paths that could prove vital for shield design optimization. Illustrative examples are provided. The connection between the current paper and the excellent work completed by M. L. Williams in 1991 is also discussed

  10. Improving the performance of industrial clarifiers using three-dimensional computational fluid dynamics

    Directory of Open Access Journals (Sweden)

    Shankhadeep Das

    2016-01-01

    Full Text Available Sedimentation is one of the most popular wastewater treatment processes, and is used to separate solid particles from carrier fluid in settling tanks known as clarifiers. The clarifier, as the last major facility in wastewater treatment plants (WWTPs, can limit or define the performance of the overall WWTP. This paper presents a novel three-dimensional unsteady computational fluid dynamics (CFD model to improve the efficiency of an industrial clarifier that had been experiencing underperformance and reduction in wastewater handling capacity. We propose a numerical technique to address the transient process of removing sludge from the floor of clarifiers by using rotating rakes. The CFD model was first applied to analyzing the ramifications of the current clarifier geometry on performance. The results show that the root causes for underperformance are related to the unconventional top side feed design of the clarifier, which leads to significant asymmetry in the flow distribution. The CFD model was next used to investigate various design modifications with the goal of improving the clarifier performance. A few geometry modification ideas such as an inward baffle, dissipating inlets, and a submerged skirt were found to create a more uniform flow distribution in the clarifier, significantly reducing the backflow into the feedwell and the velocity of the flow exiting the feedwell, which helps the solid particles to settle in the clarifier. These three designs were found to reduce the effluent total suspended solids (TSS by more than 80% and thus significantly improve clarifier performance. It is believed that the CFD model developed in this study can become a computationally efficient tool for investigating the performance of industrial clarifiers with complex geometries and rotating rakes.

  11. Construction and assessment of hierarchical edge elements for three-dimensional computations of eddy currents

    Energy Technology Data Exchange (ETDEWEB)

    Midtgaard, Ole-Morten

    1997-12-31

    This thesis considers the feasibility of doing calculations to optimize electrical machines without the need to build expensive prototypes. It deals with the construction and assessment of new, hierarchical, hexahedral edge elements for three-dimensional computations of eddy currents with the electric vector potential formulation. The new elements, five in all, gave up to second-order approximations for both the magnetic field and the current density. Theoretical arguments showed these elements to be more economical for a given polynomial order of the approximated fields than the serendipity family of nodal elements. Further it was pointed out how the support of a source field computed by using edge elements could be made very small provided that a proper spanning tree was used in the edge element mesh. This was exploited for the voltage forcing technique, where source fields were used as basis functions, with unknown total currents in voltage forced conductors as degrees of freedom. The practical assessment of the edge elements proved the accuracy to improve with increasing polynomial order, both for local and global quantities. The most economical element was, however, one giving only complete first-order approximations for both fields. Further, the edge elements turned out to be better than the nodal elements also in practice. For the voltage forcing technique, source field basis functions which had small support, resulted in large reduction of the CPU-time for solving the main equation system, compared to source fields which had large support. The new elements can be used in a p-type adaptive scheme, and they should also be applicable for other tangentially continuous field problems. 67 refs., 34 figs., 10 tabs.

  12. Three-dimensional reconstruction of axonemal outer dynein arms in situ by electron tomography.

    Science.gov (United States)

    Lupetti, Pietro; Lanzavecchia, Salvatore; Mercati, David; Cantele, Francesca; Dallai, Romano; Mencarelli, Caterina

    2005-10-01

    We present here for the first time a 3D reconstruction of in situ axonemal outer dynein arms. This reconstruction has been obtained by electron tomography applied to a series of tilted images collected from metal replicas of rapidly frozen, cryofractured, and metal-replicated sperm axonemes of the cecidomid dipteran Monarthropalpus flavus. This peculiar axonemal model consists of several microtubular laminae that proved to be particularly suitable for this type of analysis. These laminae are sufficiently planar to allow the visualization of many dynein molecules within the same fracture face, allowing us to recover a significant number of equivalent objects and to improve the signal-to-noise ratio of the reconstruction by applying advanced averaging protocols. The 3D model we obtained showed the following interesting structural features: First, each dynein arm has two head domains that are almost parallel and are obliquely oriented with respect to the longitudinal axis of microtubules. The two heads are therefore positioned at different distances from the surface of the A-tubule. Second, each head domain consists of a series of globular subdomains that are positioned on the same plane. Third, a stalk domain originates as a conical region from the proximal head and ends with a small globular domain that contacts the B-tubule. Fourth, the stem region comprises several globular subdomains and presents two distinct points of anchorage to the surface of the A-tubule. Finally, and most importantly, contrary to what has been observed in isolated dynein molecules adsorbed to flat surfaces, the stalk and the stem domains are not in the same plane as the head.

  13. Three-Dimensional Analysis of Enamel Crack Behavior Using Optical Coherence Tomography.

    Science.gov (United States)

    Segarra, M S; Shimada, Y; Sadr, A; Sumi, Y; Tagami, J

    2017-03-01

    The aim of this study was to nondestructively analyze enamel crack behavior on different areas of teeth using 3D swept source-optical coherence tomography (SS-OCT). Ten freshly extracted human teeth of each type on each arch ( n = 80 teeth) were inspected for enamel crack patterns on functional, contact and nonfunctional, or noncontact areas using 3D SS-OCT. The predominant crack pattern for each location on each specimen was noted and analyzed. The OCT observations were validated by direct observations of sectioned specimens under confocal laser scanning microscopy (CLSM). Cracks appeared as bright lines with SS-OCT, with 3 crack patterns identified: Type I - superficial horizontal cracks; Type II - vertically (occluso-gingival) oriented cracks; and Type III - hybrid or complicated cracks, a combination of a Type I and Type III cracks, which may or may not be confluent with each other. Type II cracks were predominant on noncontacting surfaces of incisors and canines and nonfunctional cusps of posterior teeth. Type I and III cracks were predominant on the contacting surfaces of incisors, cusps of canines, and functional cusps of posterior teeth. Cracks originating from the dental-enamel junction and enamel tufts, crack deflections, and the initiation of new cracks within the enamel (internal cracks) were observed as bright areas. CLSM observations corroborated the SS-OCT findings. We found that crack pattern, tooth type, and the location of the crack on the tooth exhibited a strong correlation. We show that the use of 3D SS-OCT permits for the nondestructive 3D imaging and analysis of enamel crack behavior in whole human teeth in vitro. 3D SS-OCT possesses potential for use in clinical studies for the analysis of enamel crack behavior.

  14. Three-dimensional mapping of peripapillary retinal layers using a spectral domain optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Hashmani N

    2017-12-01

    Full Text Available Nauman Hashmani, Sharif Hashmani Department of Ophthalmology, Hashmanis Hospital, Karachi, Pakistan Purpose: To map and view the effects of age, gender, and axial length on seven individual retinal layers around the optic nerve head (ONH.Methods: We scanned 242 healthy patients using the Spectralis spectral domain optical coherence tomography in an outpatient setting. The layers were observed on the Early Treatment Diabetic Retinopathy Study sectors using the standard Spectralis Family Acquisition Module 6.0.11.0. The center was the ONH, the inner circle (IC was 1–3 mm away, and the outer circle (OC was 3–6 mm away. The seven layers were retinal nerve fiber layer (RNFL, ganglion cell layer (GCL, inner plexiform layer (IPL, inner nuclear layer (INL, outer plexiform layer (OPL, outer nuclear layer (ONL, and retinal pigment epithelium (RPE. Additionally, we calculated the mean thickness of two combined layers: inner retinal layer (IRL and photoreceptor layer (PL. Finally, we measured the mean of the total retinal thickness (TRT.Results: The TRT was highest at the inferior end in the IC and at the nasal end in the OC. The RPE (p<0.001 and PL (p<0.001 were thicker in males; however, the IRL (p=0.015 was thicker in females. We found that the RNFL (p<0.001, r=0.139, GCL (p<0.001, r=0.116, IPL (p=0.016, r=0.059, INL (p<0.001, r=0.104, OPL (p=0.009, r=0.064, ONL (p<0.001, r=0.157, RPE (p=0.001, r=0.079, IRL (p<0.001, r=0.190, PL (p=0.030, r=0.053, and TRT (p<0.001, r=0.191 correlated negatively with age. The axial length significantly and negatively correlated at the GCL (p=0.003, r=0.093, IPL (p=0.020, r=0.072, INL (p=0.018, r=0.073, ONL (p<0.001, r=0.110, IRL (p=0.003, r=0.092, and TRT (p=0.003, r=0.094. We found poor reproducibility in the IC; however, this was excellent in the OC.Conclusion: We found significant differences in layers according to age, gender, and axial length. Additionally, reproducibility can be improved by altering the

  15. Three-dimensional organization of pKi-67: a comparative fluorescence and electron tomography study using FluoroNanogold.

    Science.gov (United States)

    Cheutin, Thierry; O'Donohue, Marie-Françoise; Beorchia, Adrien; Klein, Christophe; Kaplan, Hervé; Ploton, Dominique

    2003-11-01

    The monoclonal antibody (MAb) Ki-67 is routinely used in clinical studies to estimate the growth fraction of tumors. However, the role of pKi-67, the protein detected by the Ki-67 MAb, remains elusive, although some biochemical data strongly suggest that it might organize chromatin. To better understand the functional organization of pKi-67, we studied its three-dimensional distribution in interphase cells by confocal microscopy and electron tomography. FluoroNanogold, a single probe combining a dense marker with a fluorescent dye, was used to investigate pKi-67 organization at the optical and ultrastructural levels. Observation by confocal microscopy followed by 3D reconstruction showed that pKi-67 forms a shell around the nucleoli. Double labeling experiments revealed that pKi-67 co-localizes with perinucleolar heterochromatin. Electron microscopy studies confirmed this close association and demonstrated that pKi-67 is located neither in the fibrillar nor in the granular components of the nucleolus. Finally, spatial analyses by electron tomography showed that pKi-67 forms cords 250-300 nm in diameter, which are themselves composed of 30-50-nm-thick fibers. These detailed comparative in situ analyses strongly suggest the involvement of pKi-67 in the higher-order organization of perinucleolar chromatin.

  16. Three dimensional microstructural characterization of nanoscale precipitates in AA7075-T651 by focused ion beam (FIB) tomography

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Sudhanshu S.; Loza, Jose J. [Materials Science and Engineering, Arizona State University, Tempe, AZ 85287–6106 (United States); Merkle, Arno P. [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA (United States); Chawla, Nikhilesh, E-mail: nchawla@asu.edu [Materials Science and Engineering, Arizona State University, Tempe, AZ 85287–6106 (United States)

    2016-08-15

    The size and distribution of precipitates in Al 7075 alloys affects both the mechanical and corrosion behavior (including stress corrosion cracking and fatigue corrosion) of the alloy. Three dimensional (3D) quantitative microstructural analysis of Al 7075 in the peak aged condition (T651) allows for a better understanding of these behaviors. In this study, Focused ion beam (FIB) tomography was used to characterize the microstructure in three dimensions. Analysis of grains and precipitates was performed in terms of volume, size, and morphology. It was found that the precipitates at the grain boundaries are larger in size, higher in aspect ratios and maximum Feret diameter compared to the precipitates inside the grains, due to earlier nucleation of the precipitates at the grain boundaries. Our data on the precipitates at the interface between grains and Mg{sub 2}Si inclusion show that the surfaces of inclusion (impurity) particles can serve as a location for heterogeneous nucleation of precipitates. - Highlights: •Focused ion beam (FIB) tomography was used to characterize the microstructure of Al 7075 in three dimensions. •Analysis of grains and precipitates was performed in terms of volume, size, and morphology. •Precipitates at the grain boundaries have larger size and aspect ratio compared to the precipitates inside the grains.

  17. Three-dimensional structure of laser-modified Ti6Al4V and bone interface revealed with STEM tomography

    International Nuclear Information System (INIS)

    Grandfield, Kathryn; Palmquist, Anders; Engqvist, Håkan

    2013-01-01

    The early interaction between an implant's surface and bone is a leading factor for implant success, where multiple surface properties contribute to improved bone anchorage. An important parameter is surface topography, both on the micron and nanoscale. Laser-modification has been performed in the thread valleys of Ti6Al4V screws to alter their surface chemistry and topography to form a nanostructured surface titanium-dioxide. Implants were placed in the rabbit tibia, removed with surrounding bone after 8 weeks, fixated, dried and resin embedded. Focused ion beam milling (FIB) was used to prepare specimens from the resin blocks for transmission electron microscopy (TEM). Z-contrast electron tomography offered the possibility to explore the interfacial structure with high-resolution in three-dimensions. With this technique, collagen fibers of the surrounding bone appear to have been laid down parallel to the implant surface. Accordingly, visualization of the laser-modified interface with nanoscale three-dimensional resolution, as offered by Z-contrast electron tomography, gives new insights into bone bonding mechanisms between roughened titanium-dioxide surfaces and bone

  18. 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 ...

  19. Three-dimensional imaging using computer-generated holograms synthesized from 3-D Fourier spectra

    International Nuclear Information System (INIS)

    Yatagai, Toyohiko; Miura, Ken-ichi; Sando, Yusuke; Itoh, Masahide

    2008-01-01

    Computer-generated holograms(CGHs) synthesized from projection images of real existing objects are considered. A series of projection images are recorded both vertically and horizontally with an incoherent light source and a color CCD. According to the principles of computer tomography(CT), the 3-D Fourier spectrum is calculated from several projection images of objects and the Fresnel CGH is synthesized using a part of the 3-D Fourier spectrum. This method has following advantages. At first, no-blur reconstructed images in any direction are obtained owing to two-dimensionally scanning in recording. Secondarily, since not interference fringes but simple projection images of objects are recorded, a coherent light source is not necessary. Moreover, when a color CCD is used in recording, it is easily possible to record and reconstruct colorful objects. Finally, we demonstrate reconstruction of biological objects.

  20. Three-dimensional imaging using computer-generated holograms synthesized from 3-D Fourier spectra

    Energy Technology Data Exchange (ETDEWEB)

    Yatagai, Toyohiko; Miura, Ken-ichi; Sando, Yusuke; Itoh, Masahide [University of Tsukba, Institute of Applied Physics, Tennoudai 1-1-1, Tsukuba, Ibaraki 305-8571 (Japan)], E-mail: yatagai@cc.utsunomiya-u.ac.jp

    2008-11-01

    Computer-generated holograms(CGHs) synthesized from projection images of real existing objects are considered. A series of projection images are recorded both vertically and horizontally with an incoherent light source and a color CCD. According to the principles of computer tomography(CT), the 3-D Fourier spectrum is calculated from several projection images of objects and the Fresnel CGH is synthesized using a part of the 3-D Fourier spectrum. This method has following advantages. At first, no-blur reconstructed images in any direction are obtained owing to two-dimensionally scanning in recording. Secondarily, since not interference fringes but simple projection images of objects are recorded, a coherent light source is not necessary. Moreover, when a color CCD is used in recording, it is easily possible to record and reconstruct colorful objects. Finally, we demonstrate reconstruction of biological objects.

  1. Application of computer generated color graphic techniques to the processing and display of three dimensional fluid dynamic data

    Science.gov (United States)

    Anderson, B. H.; Putt, C. W.; Giamati, C. C.

    1981-01-01

    Color coding techniques used in the processing of remote sensing imagery were adapted and applied to the fluid dynamics problems associated with turbofan mixer nozzles. The computer generated color graphics were found to be useful in reconstructing the measured flow field from low resolution experimental data to give more physical meaning to this information and in scanning and interpreting the large volume of computer generated data from the three dimensional viscous computer code used in the analysis.

  2. The Impact of Three-Dimensional Computational Modeling on Student Understanding of Astronomy Concepts: A Qualitative Analysis. Research Report

    Science.gov (United States)

    Hansen, John A.; Barnett, Michael; MaKinster, James G.; Keating, Thomas

    2004-01-01

    In this study, we explore an alternate mode for teaching and learning the dynamic, three-dimensional (3D) relationships that are central to understanding astronomical concepts. To this end, we implemented an innovative undergraduate course in which we used inexpensive computer modeling tools. As the second of a two-paper series, this report…

  3. Three-dimensional reconstruction of colorectal tumors from serial tissue sections by computer graphics: a preliminary study.

    Science.gov (United States)

    Kikuchi, S; Matsuzaki, H; Kondo, K; Ohtani, Y; Ihara, A; Hiki, Y; Kakita, A; Kuwao, S

    2000-01-01

    We present herein the three-dimensional reconstruction of colorectal tumors, with particular reference to growth pattern into each layer of the colorectal wall, and measurement of tumor volume and surface area. Conventional tissue section images of colorectal tumors were analyzed using a computer graphics analysis program. The two-dimensional extent of invasion by each tumor into each layer of intestinal wall were determined from the images of each section. Based on data from multiple sections, tumor and surrounding normal tissue layers were reconstructed three-dimensionally, and volume and surface area of the tumors were determined. Using this technique, three-dimensional morphology of tumor and tumor progression into colorectal wall could be determined. Volume and surface area of the colon tumor were 4871 mm3 and 1741 mm2, respectively. Volume and surface area of the rectal tumor were 1090 mm3 and 877 mm2, respectively. This technique may provide a new approach for pathological analysis of colorectal carcinoma.

  4. Heterogeneous slip and rupture models of the San Andreas fault zone based upon three-dimensional earthquake tomography

    Energy Technology Data Exchange (ETDEWEB)

    Foxall, William [Univ. of California, Berkeley, CA (United States)

    1992-11-01

    Crystal fault zones exhibit spatially heterogeneous slip behavior at all scales, slip being partitioned between stable frictional sliding, or fault creep, and unstable earthquake rupture. An understanding the mechanisms underlying slip segmentation is fundamental to research into fault dynamics and the physics of earthquake generation. This thesis investigates the influence that large-scale along-strike heterogeneity in fault zone lithology has on slip segmentation. Large-scale transitions from the stable block sliding of the Central 4D Creeping Section of the San Andreas, fault to the locked 1906 and 1857 earthquake segments takes place along the Loma Prieta and Parkfield sections of the fault, respectively, the transitions being accomplished in part by the generation of earthquakes in the magnitude range 6 (Parkfield) to 7 (Loma Prieta). Information on sub-surface lithology interpreted from the Loma Prieta and Parkfield three-dimensional crustal velocity models computed by Michelini (1991) is integrated with information on slip behavior provided by the distributions of earthquakes located using, the three-dimensional models and by surface creep data to study the relationships between large-scale lithological heterogeneity and slip segmentation along these two sections of the fault zone.

  5. Locomotion in ornithischian dinosaurs: an assessment using three-dimensional computational modelling.

    Science.gov (United States)

    Maidment, Susannah C R; Bates, Karl T; Falkingham, Peter L; VanBuren, Collin; Arbour, Victoria; Barrett, Paul M

    2014-08-01

    Ornithischian dinosaurs were primitively bipedal with forelimbs modified for grasping, but quadrupedalism evolved in the clade on at least three occasions independently. Outside of Ornithischia, quadrupedality from bipedal ancestors has only evolved on two other occasions, making this one of the rarest locomotory transitions in tetrapod evolutionary history. The osteological and myological changes associated with these transitions have only recently been documented, and the biomechanical consequences of these changes remain to be examined. Here, we review previous approaches to understanding locomotion in extinct animals, which can be broadly split into form-function approaches using analogy based on extant animals, limb-bone scaling, and computational approaches. We then carry out the first systematic attempt to quantify changes in locomotor muscle function in bipedal and quadrupedal ornithischian dinosaurs. Using three-dimensional computational modelling of the major pelvic locomotor muscle moment arms, we examine similarities and differences among individual taxa, between quadrupedal and bipedal taxa, and among taxa representing the three major ornithischian lineages (Thyreophora, Ornithopoda, Marginocephalia). Our results suggest that the ceratopsid Chasmosaurus and the ornithopod Hypsilophodon have relatively low moment arms for most muscles and most functions, perhaps suggesting poor locomotor performance in these taxa. Quadrupeds have higher abductor moment arms than bipeds, which we suggest is due to the overall wider bodies of the quadrupeds modelled. A peak in extensor moment arms at more extended hip angles and lower medial rotator moment arms in quadrupeds than in bipeds may be due to a more columnar hindlimb and loss of medial rotation as a form of lateral limb support in quadrupeds. We are not able to identify trends in moment arm evolution across Ornithischia as a whole, suggesting that the bipedal ancestry of ornithischians did not constrain the

  6. Interferograms, schlieren, and shadowgraphs constructed from real- and ideal-gas, two- and three-dimensional computed flowfields

    Science.gov (United States)

    Yates, Leslie A.

    1993-01-01

    The construction of interferograms, schlieren, and shadowgraphs from computed flowfield solutions permits one-to-one comparisons of computed and experimental results. A method of constructing these images from both ideal- and real-gas, two and three-dimensional computed flowfields is described. The computational grids can be structured or unstructured, and multiple grids are an option. Constructed images are shown for several types of computed flows including nozzle, wake, and reacting flows; comparisons to experimental images are also shown. In addition, th sensitivity of these images to errors in the flowfield solution is demonstrated, and the constructed images can be used to identify problem areas in the computations.

  7. Assessment of Normal Eyeball Protrusion Using Computed Tomographic Imaging and Three-Dimensional Reconstruction in Korean Adults.

    Science.gov (United States)

    Shin, Kang-Jae; Gil, Young-Chun; Lee, Shin-Hyo; Kim, Jeong-Nam; Yoo, Ja-Young; Kim, Soon-Heum; Choi, Hyun-Gon; Shin, Hyun Jin; Koh, Ki-Seok; Song, Wu-Chul

    2017-01-01

    The aim of the present study was to assess normal eyeball protrusion from the orbital rim using two- and three-dimensional images and demonstrate the better suitability of CT images for assessment of exophthalmos. The facial computed tomographic (CT) images of Korean adults were acquired in sagittal and transverse views. The CT images were used in reconstructing three-dimensional volume of faces using computer software. The protrusion distances from orbital rims and the diameters of eyeballs were measured in the two views of the CT image and three-dimensional volume of the face. Relative exophthalmometry was calculated by the difference in protrusion distance between the right and left sides. The eyeball protrusion was 4.9 and 12.5 mm in sagittal and transverse views, respectively. The protrusion distances were 2.9 mm in the three-dimensional volume of face. There were no significant differences between right and left sides in the degree of protrusion, and the difference was within 2 mm in more than 90% of the subjects. The results of the present study will provide reliable criteria for precise diagnosis and postoperative monitoring using CT imaging of diseases such as thyroid-associated ophthalmopathy and orbital tumors.

  8. 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 ...

  9. Computed Tomography (CT) -- Head

    Medline Plus

    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) - ...

  10. Three-dimensional Upper Crustal Velocity and Attenuation Structures of the Central Tibetan Plateau from Local Earthquake Tomography

    Science.gov (United States)

    Zhou, B.; Liang, X.; Lin, G.; Tian, X.; Zhu, G.; Mechie, J.; Teng, J.

    2017-12-01

    A series of V-shaped conjugate strike-slip faults are the most spectacular geologic features in the central Tibetan plateau. A previous study suggested that this conjugate strike-slip fault system accommodates the east-west extension and coeval north-south contraction. Another previous study suggested that the continuous convergence between the Indian and Eurasian continents and the eastward asthenospheric flow generated lithospheric paired general-shear (PGS) deformation, which then caused the development of conjugate strike-slip faults in central Tibet. Local seismic tomography can image three dimensional upper-crustal velocity and attenuation structures in central Tibet, which will provide us with more information about the spatial distribution of physical properties and compositional variations around the conjugate strike-slip fault zone. Ultimately, this information could improve our understanding of the development mechanism of the conjugate strike-slip fault system. In this study, we collected 6,809 Pg and 2,929 Sg arrival times from 414 earthquakes recorded by the temporary SANDWICH and permanent CNSN networks from November 2013 to November 2015. We also included 300 P and 17 S arrival times from 12 shots recorded by the INDEPTH III project during the summer of 1998 in the velocity tomography. We inverted for preliminary Vp and Vp/Vs models using the SIMUL2000 tomography algorithm, and then relocated the earthquakes with these preliminary velocity models. After that, we inverted for the final velocity models with these improved source locations and origin times. After the velocity inversion, we performed local attenuation tomography using t* measurements from the same dataset with an already existing approach. There are correlated features in the velocity and attenuation structures. From the surface to 10 km depth, the study area is dominated by high Vp and Qp anomalies. However, from 10 km to 20 km depth, there is a low Vp and Qp zone distributed along the

  11. Automated framework for intraretinal cystoid macular edema segmentation in three-dimensional optical coherence tomography images with macular hole

    Science.gov (United States)

    Zhu, Weifang; Zhang, Li; Shi, Fei; Xiang, Dehui; Wang, Lirong; Guo, Jingyun; Yang, Xiaoling; Chen, Haoyu; Chen, Xinjian

    2017-07-01

    Cystoid macular edema (CME) and macular hole (MH) are the leading causes for visual loss in retinal diseases. The volume of the CMEs can be an accurate predictor for visual prognosis. This paper presents an automatic method to segment the CMEs from the abnormal retina with coexistence of MH in three-dimensional-optical coherence tomography images. The proposed framework consists of preprocessing and CMEs segmentation. The preprocessing part includes denoising, intraretinal layers segmentation and flattening, and MH and vessel silhouettes exclusion. In the CMEs segmentation, a three-step strategy is applied. First, an AdaBoost classifier trained with 57 features is employed to generate the initialization results. Second, an automated shape-constrained graph cut algorithm is applied to obtain the refined results. Finally, cyst area information is used to remove false positives (FPs). The method was evaluated on 19 eyes with coexistence of CMEs and MH from 18 subjects. The true positive volume fraction, FP volume fraction, dice similarity coefficient, and accuracy rate for CMEs segmentation were 81.0%±7.8%, 0.80%±0.63%, 80.9%±5.7%, and 99.7%±0.1%, respectively.

  12. Three-dimensional imaging analysis of Yersinia ruckeri infected rainbow trout (Oncorhynchus mykiss) gills by optical projection tomography

    DEFF Research Database (Denmark)

    Otani, Maki; Raida, Martin Kristian

    Optical projection tomography (OPT) is a new tool for three-dimensional (3D) imaging of small tissues or embryos, based on multi-angle recording of internal fluorescent signals using intact whole mount tissue or fish. To understand the route of infection, gills of Y. ruckeri infected rainbow trout...... were labeled with fluorescent antibody and visualized in 3D by the OPT scanner. Rainbow trout were infected with Y. ruckeri O1 biotype 1 (1 x 109 cells/ml) for 1 hour at 18 °C, and then transferred to clean water. Three fish were sampled at 12 different time points and fixed in 4% PFA. The gills were...... incubated whole with rabbit anti-Y. ruckeri polyclonal antibody and Alexa Fluor®594 conjugated goat anti-rabbit IgG. After embedding in 1% low melting point agarose, specimens were dehydrated in 100% methanol and cleared in BABB (benzyl alcohol: benzyl benzoate) for OPT scanning. 3D imaging results showed...

  13. Comparison of Diagnostic Performance of Three-Dimensional Positron Emission Mammography versus Whole Body Positron Emission Tomography in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Dong Dai

    2017-01-01

    Full Text Available Objective. To compare the diagnostic performance of three-dimensional (3D positron emission mammography (PEM versus whole body positron emission tomography (WBPET for breast cancer. Methods. A total of 410 women with normal breast or benign or highly suspicious malignant tumors were randomized at 1 : 1 ratio to undergo 3D-PEM followed by WBPET or WBPET followed by 3D-PEM. Lumpectomy or mastectomy was performed on eligible participants after the scanning. Results. The sensitivity and specificity of 3D-PEM were 92.8% and 54.5%, respectively. WBPET showed a sensitivity of 95.7% and specificity of 56.8%. After exclusion of the patients with lesions beyond the detecting range of the 3D-PEM instrument, 3D-PEM showed higher sensitivity than WBPET (97.0% versus 95.5%, P = 0.913, particularly for small lesions (<1 cm (72.0% versus 60.0%, P = 0.685. Conclusions. The 3D-PEM appears more sensitive to small lesions than WBPET but may fail to detect lesions that are beyond the detecting range. This study was approved by the Ethics Committee (E2012052 at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China. The instrument positron emission mammography (PEMi was approved by China State Food and Drug Administration under the registration number 20153331166.

  14. Comparing three-dimensional serial optical coherence tomography histology to MRI imaging in the entire mouse brain

    Science.gov (United States)

    Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Lesage, Frédéric

    2018-01-01

    An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size of (4.9×4.9×6.5) μm3 stitched back together to give a three-dimensional map of the brain from which a template OCT brain was obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, OCT datasets were compared to both in vivo and ex vivo magnetic resonance imaging (MRI) imaging. The OCT brain template yielded a highly detailed map of the brain structure, with a high contrast in white matter fiber bundles and was highly resemblant to the in vivo MRI template. Brain labeling using the Allen brain framework showed little variation in regional brain volume among imaging modalities with no statistical differences. The high correspondence between the OCT template brain and its in vivo counterpart demonstrates the potential of whole brain histology to validate in vivo imaging.

  15. Computed tomography intravenous cholangiography

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  16. The use of computed tomographic three-dimensional reconstructions to develop instructional models for equine pelvic ultrasonography.

    Science.gov (United States)

    Whitcomb, Mary Beth; Doval, John; Peters, Jason

    2011-01-01

    Ultrasonography has gained increased utility to diagnose pelvic fractures in horses; however, internal pelvic contours can be difficult to appreciate from external palpable landmarks. We developed three-dimensional (3D) simulations of the pelvic ultrasonographic examination to assist with translation of pelvic contours into two-dimensional (2D) images. Contiguous 1mm transverse computed tomography (CT) images were acquired through an equine femur and hemipelvis using a single slice helical scanner. 3D surface models were created using a DICOM reader and imported into a 3D modeling and animation program. The bone models were combined with a purchased 3D horse model and the skin made translucent to visualize pelvic surface contours. 3D models of ultrasound transducers were made from reference photos, and a thin sector shape was created to depict the ultrasound beam. Ultrasonographic examinations were simulated by moving transducers on the skin surface and rectally to produce images of pelvic structures. Camera angles were manipulated to best illustrate the transducer-beam-bone interface. Fractures were created in multiple configurations. Animations were exported as QuickTime movie files for use in presentations coupled with corresponding ultrasound videoclips. 3D models provide a link between ultrasonographic technique and image generation by depicting the interaction of the transducer, ultrasound beam, and structure of interest. The horse model was important to facilitate understanding of the location of pelvic structures relative to the skin surface. While CT acquisition time was brief, manipulation within the 3D software program was time intensive. Results were worthwhile from an instructional standpoint based on user feedback. © 2011 Veterinary Radiology & Ultrasound.

  17. Computed tomography

    International Nuclear Information System (INIS)

    Boyd, D.P.

    1989-01-01

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

  18. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  19. 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)

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    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 ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

    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 ...

  2. STEADY-SHIP: a computer code for three-dimensional nuclear and thermal-hydraulic analyses of marine reactors

    International Nuclear Information System (INIS)

    Itagaki, Masafumi; Naito, Yoshitaka; Tokuno, Yukio; Matsui, Yasushi.

    1988-01-01

    A code STEADY-SHIP has been developed to calculate three-dimensional distributions of neutron flux, power and coolant temperature in the reactor core of the nuclear ship MUTSU. The code consists of two parts, that is, a few-group three-dimensional neutron diffusion module DIFFUSION-SHIP and a thermal-hydraulic module HYDRO-SHIP: In the DIFFUSION-SHIP the leakage iteration method is used for solving the three-dimensional neutron diffusion equation with small computer core memory and short computing time; The HYDRO-SHIP performs the general thermal-hydraulic calculation for evaluating feedbacks required in the neutronic calculation by the DIFFUSION-SHIP. The macroscopic nuclear constants are generated by a module CROSS-SHIP as functions of xenon poison, fuel temperature, moderator temperature and moderator density. A module LOCAL-FINE has the capability of computing a detailed rod power distribution for each local node in the core, using the boundary conditions on the surface of the node which were supplied by the STEADY-SHIP whole-core calculation. The applicability of this code to marine reactors has been demonstrated by comparing the computed results with the data measured during the MUTSU land-loaded core critical experiments and with the data obtained during the hot-zero-power tests performed for the actual MUTSU plant. (author)

  3. Development of three-dimensional neoclassical transport simulation code with high performance Fortran on a vector-parallel computer

    International Nuclear Information System (INIS)

    Satake, Shinsuke; Okamoto, Masao; Nakajima, Noriyoshi; Takamaru, Hisanori

    2005-11-01

    A neoclassical transport simulation code (FORTEC-3D) applicable to three-dimensional configurations has been developed using High Performance Fortran (HPF). Adoption of computing techniques for parallelization and a hybrid simulation model to the δf Monte-Carlo method transport simulation, including non-local transport effects in three-dimensional configurations, makes it possible to simulate the dynamism of global, non-local transport phenomena with a self-consistent radial electric field within a reasonable computation time. In this paper, development of the transport code using HPF is reported. Optimization techniques in order to achieve both high vectorization and parallelization efficiency, adoption of a parallel random number generator, and also benchmark results, are shown. (author)

  4. Three-dimensional multislice spiral computed tomographic angiography: a potentially useful tool for safer free tissue transfer to complicated regions

    DEFF Research Database (Denmark)

    Demirtas, Yener; Cifci, Mehmet; Kelahmetoglu, Osman

    2009-01-01

    Three-dimensional multislice spiral computed tomographic angiography (3D-MSCTA) is a minimally invasive method of vascular mapping. The aim of this study was to evaluate the clinical usefulness of this imaging technique in delineating the recipient vessels for safer free tissue transfer to compli......Three-dimensional multislice spiral computed tomographic angiography (3D-MSCTA) is a minimally invasive method of vascular mapping. The aim of this study was to evaluate the clinical usefulness of this imaging technique in delineating the recipient vessels for safer free tissue transfer...... be kept in mind, especially inthe patients with peripheral vascular disease. 3D-MSCTA has the potential to replace digital subtraction angiography for planning of microvascular reconstructions and newer devices with higher resolutions will probably increase the reliability of this technique. (c) 2009...

  5. Cone beam computed tomography in Endodontics - a review

    NARCIS (Netherlands)

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

    2015-01-01

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

  6. Three-dimensional segmentation of the tumor mass in computed tomographic images of neuroblastoma

    Science.gov (United States)

    Deglint, Hanford J.; Rangayyan, Rangaraj M.; Boag, Graham S.

    2004-05-01

    Tumor definition and diagnosis require the analysis of the spatial distribution and Hounsfield unit (HU) values of voxels in computed tomography (CT) images, coupled with a knowledge of normal anatomy. Segmentation of the tumor in neuroblastoma is complicated by the fact that the mass is almost always heterogeneous in nature; furthermore, viable tumor, necrosis, fibrosis, and normal tissue are often intermixed. Rather than attempt to separate these tissue types into distinct regions, we propose to explore methods to delineate the normal structures expected in abdominal CT images, remove them from further consideration, and examine the remaining parts of the images for the tumor mass. We explore the use of fuzzy connectivity for this purpose. Expert knowledge provided by the radiologist in the form of the expected structures and their shapes, HU values, and radiological characteristics are also incorporated in the segmentation algorithm. Segmentation and analysis of the tissue composition of the tumor can assist in quantitative assessment of the response to chemotherapy and in the planning of delayed surgery for resection of the tumor. The performance of the algorithm is evaluated using cases acquired from the Alberta Children's Hospital.

  7. User's guide to HEATRAN: a computer program for three-dimensional transient fluid-flow and heat-transfer analysis

    International Nuclear Information System (INIS)

    Wong, C.N.C.; Cheng, S.K.; Todreas, N.E.

    1982-01-01

    This report provides the HEATRAN user with programming and input information. HEATRAN is a computer program which is written to analyze the transient three dimensional single phase incompressible fluid flow and heat transfer problem. In this report, the programming information is given first. This information includes details concerning the code and structure. The description of the required input variables is presented next. Following the input description, the sample problems are described and HEATRAN's results are presented

  8. Quadcopter control in three-dimensional space using a noninvasive motor imagery based brain-computer interface

    Science.gov (United States)

    LaFleur, Karl; Cassady, Kaitlin; Doud, Alexander; Shades, Kaleb; Rogin, Eitan; He, Bin

    2013-01-01

    Objective At the balanced intersection of human and machine adaptation is found the optimally functioning brain-computer interface (BCI). In this study, we report a novel experiment of BCI controlling a robotic quadcopter in three-dimensional physical space using noninvasive scalp EEG in human subjects. We then quantify the performance of this system using metrics suitable for asynchronous BCI. Lastly, we examine the impact that operation of a real world device has on subjects’ control with comparison to a two-dimensional virtual cursor task. Approach Five human subjects were trained to modulate their sensorimotor rhythms to control an AR Drone navigating a three-dimensional physical space. Visual feedback was provided via a forward facing camera on the hull of the drone. Individual subjects were able to accurately acquire up to 90.5% of all valid targets presented while travelling at an average straight-line speed of 0.69 m/s. Significance Freely exploring and interacting with the world around us is a crucial element of autonomy that is lost in the context of neurodegenerative disease. Brain-computer interfaces are systems that aim to restore or enhance a user’s ability to interact with the environment via a computer and through the use of only thought. We demonstrate for the first time the ability to control a flying robot in the three-dimensional physical space using noninvasive scalp recorded EEG in humans. Our work indicates the potential of noninvasive EEG based BCI systems to accomplish complex control in three-dimensional physical space. The present study may serve as a framework for the investigation of multidimensional non-invasive brain-computer interface control in a physical environment using telepresence robotics. PMID:23735712

  9. Study of three-dimensional Rayleigh--Taylor instability in compressible fluids through level set method and parallel computation

    International Nuclear Information System (INIS)

    Li, X.L.

    1993-01-01

    Computation of three-dimensional (3-D) Rayleigh--Taylor instability in compressible fluids is performed on a MIMD computer. A second-order TVD scheme is applied with a fully parallelized algorithm to the 3-D Euler equations. The computational program is implemented for a 3-D study of bubble evolution in the Rayleigh--Taylor instability with varying bubble aspect ratio and for large-scale simulation of a 3-D random fluid interface. The numerical solution is compared with the experimental results by Taylor

  10. Efficient computer program EPAS-J1 for calculating stress intensity factors of three-dimensional surface cracks

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Watanabe, Takayuki; Yagawa, Genki.

    1982-03-01

    A finite element computer program EPAS-J1 was developed to calculate the stress intensity factors of three-dimensional cracks. In the program, the stress intensity factor is determined by the virtual crack extension method together with the distorted elements allocated along the crack front. This program also includes the connection elements based on the Lagrange multiplier concept to connect such different kinds of elements as the solid and shell elements, or the shell and beam elements. For the structure including three-dimensional surface cracks, the solid elements are employed only at the neighborhood of a surface crack, while the remainder of the structure is modeled by the shell or beam elements due to the reason that the crack singularity is very local. Computer storage and computational time can be highly reduced with the application of the above modeling technique for the calculation of the stress intensity factors of the three-dimensional surface cracks, because the three-dimensional solid elements are required only around the crack front. Several numerical analyses were performed by the EPAS-J1 program. At first, the accuracies of the connection element and the virtual crack extension method were confirmed using the simple structures. Compared with other techniques of connecting different kinds of elements such as the tying method or the method using anisotropic plate element, the present connection element is found to provide better results than the others. It is also found that the virtual crack extension method provides the accurate stress intensity factor. Furthermore, the results are also presented for the stress intensity factor analyses of cylinders with longitudinal or circumferential surface cracks using the combination of the various kinds of elements together with the connection elements. (author)

  11. Automatic segmentation in three-dimensional analysis of fibrovascular pigmentepithelial detachment using high-definition optical coherence tomography.

    Science.gov (United States)

    Ahlers, C; Simader, C; Geitzenauer, W; Stock, G; Stetson, P; Dastmalchi, S; Schmidt-Erfurth, U

    2008-02-01

    A limited number of scans compromise conventional optical coherence tomography (OCT) to track chorioretinal disease in its full extension. Failures in edge-detection algorithms falsify the results of retinal mapping even further. High-definition-OCT (HD-OCT) is based on raster scanning and was used to visualise the localisation and volume of intra- and sub-pigment-epithelial (RPE) changes in fibrovascular pigment epithelial detachments (fPED). Two different scanning patterns were evaluated. 22 eyes with fPED were imaged using a frequency-domain, high-speed prototype of the Cirrus HD-OCT. The axial resolution was 6 mum, and the scanning speed was 25 kA scans/s. Two different scanning patterns covering an area of 6 x 6 mm in the macular retina were compared. Three-dimensional topographic reconstructions and volume calculations were performed using MATLAB-based automatic segmentation software. Detailed information about layer-specific distribution of fluid accumulation and volumetric measurements can be obtained for retinal- and sub-RPE volumes. Both raster scans show a high correlation (p0.89) of measured values, that is PED volume/area, retinal volume and mean retinal thickness. Quality control of the automatic segmentation revealed reasonable results in over 90% of the examinations. Automatic segmentation allows for detailed quantitative and topographic analysis of the RPE and the overlying retina. In fPED, the 128 x 512 scanning-pattern shows mild advantages when compared with the 256 x 256 scan. Together with the ability for automatic segmentation, HD-OCT clearly improves the clinical monitoring of chorioretinal disease by adding relevant new parameters. HD-OCT is likely capable of enhancing the understanding of pathophysiology and benefits of treatment for current anti-CNV strategies in future.

  12. Three-dimensional noninvasive monitoring iodine-131 uptake in the thyroid using a modified Cerenkov luminescence tomography approach.

    Science.gov (United States)

    Hu, Zhenhua; Ma, Xiaowei; Qu, Xiaochao; Yang, Weidong; Liang, Jimin; Wang, Jing; Tian, Jie

    2012-01-01

    Cerenkov luminescence tomography (CLT) provides the three-dimensional (3D) radiopharmaceutical biodistribution in small living animals, which is vital to biomedical imaging. However, existing single-spectral and multispectral methods are not very efficient and effective at reconstructing the distribution of the radionuclide tracer. In this paper, we present a semi-quantitative Cerenkov radiation spectral characteristic-based source reconstruction method named the hybrid spectral CLT, to efficiently reconstruct the radionuclide tracer with both encouraging reconstruction results and less acquisition and image reconstruction time. We constructed the implantation mouse model implanted with a 400 µCi Na(131)I radioactive source and the physiological mouse model received an intravenous tail injection of 400 µCi radiopharmaceutical Iodine-131 (I-131) to validate the performance of the hybrid spectral CLT and compared the reconstruction results, acquisition, and image reconstruction time with that of single-spectral and multispectral CLT. Furthermore, we performed 3D noninvasive monitoring of I-131 uptake in the thyroid and quantified I-131 uptake in vivo using hybrid spectral CLT. Results showed that the reconstruction based on the hybrid spectral CLT was more accurate in localization and quantification than using single-spectral CLT, and was more efficient in the in vivo experiment compared with multispectral CLT. Additionally, 3D visualization of longitudinal observations suggested that the reconstructed energy of I-131 uptake in the thyroid increased with acquisition time and there was a robust correlation between the reconstructed energy versus the gamma ray counts of I-131 (r(2) = 0.8240). The ex vivo biodistribution experiment further confirmed the I-131 uptake in the thyroid for hybrid spectral CLT. Results indicated that hybrid spectral CLT could be potentially used for thyroid imaging to evaluate its function and monitor its treatment for thyroid cancer.

  13. Quality of brain perfusion single-photon emission tomography images: multicentre evaluation using an anatomically accurate three-dimensional phantom

    International Nuclear Information System (INIS)

    Heikkinen, J.; Kuikka, J.T.; Ahonen, A.; Rautio, P.

    1998-01-01

    The aim of the study was to evaluate the quality of routine brain perfusion single-photon emission tomography (SPET) images in Finnish nuclear medicine laboratories. Twelve laboratories participated in the study. A three-dimensional high resolution brain phantom (Data Spectrum's 3D Hoffman Brain Phantom) was filled with a well-mixed solution of technetium-99m (110 MBq), water and detergent. Acquisition, reconstruction and printing were performed according to the clinical routine in each centre. Three nuclear medicine specialists blindly evaluated all image sets. The results were ranked from 1 to 5 (poor quality-high quality). Also a SPET performance phantom (Nuclear Associates' PET/SPECT Performance Phantom PS 101) was filled with the same radioactivity concentration as the brain phantom. The parameters for the acquisition, the reconstruction and the printing were exactly the same as with the brain phantom. The number of detected ''hot'' (from 0 to 8) and ''cold'' lesions (from 0 to 7) was visually evaluated from hard copies. Resolution and contrast were quantified from digital images. Average score for brain phantom images was 2.7±0.8 (range 1.5-4.5). The average diameter of the ''hot'' cylinders detected was 16 mm (range 9.2-20.0 mm) and that of the ''cold'' cylinders detected, 11 mm (5.9-14.3 mm) according to visual evaluation. Quantification of digital images showed that the hard copy was one reason for low-quality images. The quality of the hard copies was good only in four laboratories and was amazingly low in the others when comparing it with the actual structure of the brain phantom. The described quantification method is suitable for optimizing resolution and contrast detectability of hard copies. This study revealed the urgent need for external quality assurance of clinical brain perfusion SPET images. (orig.)

  14. Polymorphous Computing Architecture (PCA) Application Benchmark 1: Three-Dimensional Radar Data Processing

    National Research Council Canada - National Science Library

    Lebak, J

    2001-01-01

    The DARPA Polymorphous Computing Architecture (PCA) program is building advanced computer architectures that can reorganize their computation and communication structures to achieve better overall application performance...

  15. 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

  16. Small-angle X-ray scattering tensor tomography: model of the three-dimensional reciprocal-space map, reconstruction algorithm and angular sampling requirements.

    Science.gov (United States)

    Liebi, Marianne; Georgiadis, Marios; Kohlbrecher, Joachim; Holler, Mirko; Raabe, Jörg; Usov, Ivan; Menzel, Andreas; Schneider, Philipp; Bunk, Oliver; Guizar-Sicairos, Manuel

    2018-01-01

    Small-angle X-ray scattering tensor tomography, which allows reconstruction of the local three-dimensional reciprocal-space map within a three-dimensional sample as introduced by Liebi et al. [Nature (2015), 527, 349-352], is described in more detail with regard to the mathematical framework and the optimization algorithm. For the case of trabecular bone samples from vertebrae it is shown that the model of the three-dimensional reciprocal-space map using spherical harmonics can adequately describe the measured data. The method enables the determination of nanostructure orientation and degree of orientation as demonstrated previously in a single momentum transfer q range. This article presents a reconstruction of the complete reciprocal-space map for the case of bone over extended ranges of q. In addition, it is shown that uniform angular sampling and advanced regularization strategies help to reduce the amount of data required.

  17. Three-dimensional teletherapy treatment planning

    International Nuclear Information System (INIS)

    Panthaleon van Eck, R.B. van.

    1986-01-01

    This thesis deals with physical/mathematical backgrounds of computerized teletherapy treatment planning. The subjects discussed in this thesis can be subdivided into three main categories: a) Three-dimensional treatment planning. A method is evaluated which can be used for the purpose of simulation and optimization of dose distributions in three dimensions. b) The use of Computed Tomography. The use of patient information obtained from Computed Tomography for the purpose of dose computations is evaluated. c) Dose computational models for photon- and electron beams. Models are evaluated which provide information regarding the way in which the radiation dose is distributed in the patient (viz. is absorbed and/or dispersed). (Auth.)

  18. A computationally efficient simulator for three-dimensional Monte Carlo simulation of ion implantation into complex structures

    International Nuclear Information System (INIS)

    Li Di; Wang Geng; Chen Yang; Li Lin; Shrivastav, Gaurav; Oak, Stimit; Tasch, Al; Banerjee, Sanjay; Obradovic, Borna

    2001-01-01

    A physically-based three-dimensional Monte Carlo simulator has been developed within UT-MARLOWE, which is capable of simulating ion implantation into multi-material systems and arbitrary topography. Introducing the third dimension can result in a severe CPU time penalty. In order to minimize this penalty, a three-dimensional trajectory replication algorithm has been developed, implemented and verified. More than two orders of magnitude savings of CPU time have been observed. An unbalanced Octree structure was used to decompose three-dimensional structures. It effectively simplifies the structure, offers a good balance between modeling accuracy and computational efficiency, and allows arbitrary precision of mapping the Octree onto desired structure. Using the well-established and validated physical models in UT-MARLOWE 5.0, this simulator has been extensively verified by comparing the integrated one-dimensional simulation results with secondary ion mass spectroscopy (SIMS). Two options, the typical case and the worst scenario, have been selected to simulate ion implantation into poly-silicon under various scenarios using this simulator: implantation into a random, amorphous network, and implantation into the worst-case channeling condition, into (1 1 0) orientated wafers

  19. Preliminary investigations on the determination of three-dimensional dose distributions using scintillator blocks and optical tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kroll, Florian; Karsch, Leonhard [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden (Germany); Pawelke, Jörg [OncoRay - National Center for Radiation Research in Oncology, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, P.O. Box 510119, 01314 Dresden (Germany)

    2013-08-15

    Purpose: Clinical QA in teletherapy as well as the characterization of experimental radiation sources for future medical applications requires effective methods for measuring three-dimensional (3D) dose distributions generated in a water-equivalent medium. Current dosimeters based on ionization chambers, diodes, thermoluminescence detectors, radiochromic films, or polymer gels exhibit various drawbacks: High quality 3D dose determination is either very sophisticated and expensive or requires high amounts of effort and time for the preparation or read out. New detectors based on scintillator blocks in combination with optical tomography are studied, since they have the potential to facilitate the desired cost-effective, transportable, and long-term stable dosimetry system that is able to determine 3D dose distributions with high spatial resolution in a short time.Methods: A portable detector prototype was set up based on a plastic scintillator block and four digital cameras. During irradiation the scintillator emits light, which is detected by the fixed cameras. The light distribution is then reconstructed by optical tomography, using maximum-likelihood expectation maximization. The result of the reconstruction approximates the 3D dose distribution. First performance tests of the prototype using laser light were carried out. Irradiation experiments were performed with ionizing radiation, i.e., bremsstrahlung (6 to 21 MV), electrons (6 to 21 MeV), and protons (68 MeV), provided by clinical and research accelerators.Results: Laser experiments show that the current imaging properties differ from the design specifications: The imaging scale of the optical systems is position dependent, ranging from 0.185 mm/pixel to 0.225 mm/pixel. Nevertheless, the developed dosimetry method is proven to be functional for electron and proton beams. Induced radiation doses of 50 mGy or more made 3D dose reconstructions possible. Taking the imaging properties into account, determined

  20. Three-dimensional neuroimaging

    International Nuclear Information System (INIS)

    Toga, A.W.

    1990-01-01

    This book reports on new neuroimaging technologies that are revolutionizing the study of the brain be enabling investigators to visualize its structure and entire pattern of functional activity in three dimensions. The book provides a theoretical and practical explanation of the new science of creating three-dimensional computer images of the brain. The coverage includes a review of the technology and methodology of neuroimaging, the instrumentation and procedures, issues of quantification, analytic protocols, and descriptions of neuroimaging systems. Examples are given to illustrate the use of three-dimensional enuroimaging to quantitate spatial measurements, perform analysis of autoradiographic and histological studies, and study the relationship between brain structure and function

  1. The three-dimensional transient two-phase flow computer programme BACCHUS-3D/TP

    International Nuclear Information System (INIS)

    Bottoni, M.; Dorr, B.; Homann, C.

    1992-04-01

    The three-dimensional single-phase flow version of the BACCHUS code, which describes the thermal behaviour of a coolant in hexagonal bundle geometry, developed earlier, provided the basis for the development of the two-phase flow version documented in this report. A detailed description is given of the two-phase Slip Model (SM), and of the Homogeneous Equilibrium Model (HEM) as a subcase, which presents several improvements from both viewpoints of physical modelling and numerical treatment, with respect to usual models found in the literature. The most advanced Separated Phases Model (SPM) is then described in all analytical details necessary to fully understand its implementation in the code. Poblems related to the link between the two above models into an integrated code version are then discussed. The code provides an additional option for modelling of active or passive, permeable or impermeable blockages. This option is documented separately. New numerical methods for solving the algebraic systems of equations derived from the linearization of the fundamental equations have completely superseded previous ones and are explained in detail. Eventually a section is dedicated to an overview of the code verification, made over several years, which goes from steady state single-phase unheated bundle experiments up to fast transient two-phase flow experiments in electrically heated 37-pin bundles. (orig.) [de

  2. Three-dimensional interpretation of MT data in volcanic environments (computer simulation)

    Energy Technology Data Exchange (ETDEWEB)

    Spichak, V. [Geoelectromagnetic Research Institute RAS, Troitsk, Moscow (Russian Federation)

    2001-04-01

    The research is aimed, first, to find components of MT-fields and their transforms, which facilitate the imaging of the internal structure of volcanoes and, second, to study the detectability of conductivity variations in a magma chamber due to alterations of other physical parameters. The resolving power of MT data with respect to the electric structure of volcanic zones is studied using software developed by the author for three-dimensional (3D) numerical modeling, analysis and imaging. A set of 3D volcano models are constructed and synthetic MT data on the relief Earth's surface are analysed. It is found that impedance phases as well as in-phase and quadrature parts of the electric field type transforms enable the best imaging of the volcanic interior. The determinant impedance is, however, the most suitable for adequate interpretation of measurements carried out for the purpose of monitoring conductivity variations in a magma chamber. The way of removing the geological noise from the MT data by means of its upward analytical continuation to the artificial reference plane is discussed. Interpretation methodologies are suggested aimed at 3D imaging and monitoring volcanic interiors by MT data.

  3. Three-dimensional fine structure of the organization of microtubules in neurite varicosities by ultra-high voltage electron microscope tomography.

    Science.gov (United States)

    Nishida, Tomoki; Yoshimura, Ryoichi; Endo, Yasuhisa

    2017-09-01

    Neurite varicosities are highly specialized compartments that are involved in neurotransmitter/ neuromodulator release and provide a physiological platform for neural functions. However, it remains unclear how microtubule organization contributes to the form of varicosity. Here, we examine the three-dimensional structure of microtubules in varicosities of a differentiated PC12 neural cell line using ultra-high voltage electron microscope tomography. Three-dimensional imaging showed that a part of the varicosities contained an accumulation of organelles that were separated from parallel microtubule arrays. Further detailed analysis using serial sections and whole-mount tomography revealed microtubules running in a spindle shape of swelling in some other types of varicosities. These electron tomographic results showed that the structural diversity and heterogeneity of microtubule organization supported the form of varicosities, suggesting that a different distribution pattern of microtubules in varicosities is crucial to the regulation of varicosities development.

  4. Innervation pattern of the suprascapular nerve within supraspinatus: a three-dimensional computer modeling study.

    Science.gov (United States)

    Hermenegildo, J A; Roberts, S L; Kim, S Y

    2014-05-01

    The relationship between the innervation pattern of the suprascapular nerve (SSN) and the muscle architecture of supraspinatus has not been thoroughly investigated. The supraspinatus is composed of two architecturally distinct regions: anterior and posterior. Each of these regions is further subdivided into three parts: superficial, middle and deep. The purpose of this study was to investigate the course of the SSN throughout the volume of supraspinatus and to relate the intramuscular branches to the distinct regions and parts of the supraspinatus. The SSN was dissected in thirty formalin embalmed cadaveric specimens and digitized throughout the muscle volume in six of those specimens. The digitized data were modeled using Autodesk(®) Maya(®) 2011. The three-dimensional (3D) models were used to relate the intramuscular innervation pattern to the muscle and tendon architecture defined by Kim et al. (2007, Clin Anat 20:648-655). The SSN bifurcated into two main trunks: medial and lateral. All parts of the anterior region were predominantly innervated by the medial trunk and its proximal and medial branches, whereas all parts of the posterior region predominantly by the lateral trunk and its posterolateral and/or posteromedial branches. The posterior region also received innervation from the proximal branch of the medial trunk in half of the specimens. These findings provide evidence that the anterior and posterior regions are distinct with respect to their innervation. The 3D map of the innervation pattern will aid in planning future clinical studies investigating muscle activation patterns and provide insight into possible injury of the nerve with supraspinatus pathology and surgical techniques. Copyright © 2013 Wiley Periodicals, Inc.

  5. Three-dimensional pseudo-random number generator for implementing in hybrid computer systems

    International Nuclear Information System (INIS)

    Ivanov, M.A.; Vasil'ev, N.P.; Voronin, A.V.; Kravtsov, M.Yu.; Maksutov, A.A.; Spiridonov, A.A.; Khudyakova, V.I.; Chugunkov, I.V.

    2012-01-01

    The algorithm for generating pseudo-random numbers oriented to implementation by using hybrid computer systems is considered. The proposed solution is characterized by a high degree of parallel computing [ru

  6. Computer-assisted three-dimensional reconstruction of the corticospinal system as a reference for CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann, C. [Department of Neuroanatomy, Hannover Medical School (Germany)]|[University Hospital Eppendorf, Hamburg (Germany); Kretschmann, H.J. [Department of Neuroanatomy, Hannover Medical School (Germany)

    1998-09-01

    We present a three-dimensional (3D) anatomical computer-graphics model of the corticospinal system acquired from equidistant serial anatomical slices of six intracranially-fixed human brains. This model is part of a neuroanatomical reference system (NeuRef) which enables 3D visualization of the brain and shows the relationship of its components such as anatomical structures, functional fibre tracts and arteries. Sections through the models can be matched with corresponding CT or MR images. This allows the probable localisation of corticospinal fibres on CT or MRI. (orig.) (orig.) With 18 figs., 3 tabs., 40 refs.

  7. Computer-assisted three-dimensional reconstruction of the corticospinal system as a reference for CT and MRI

    International Nuclear Information System (INIS)

    Buhmann, C.; Kretschmann, H.J.

    1998-01-01

    We present a three-dimensional (3D) anatomical computer-graphics model of the corticospinal system acquired from equidistant serial anatomical slices of six intracranially-fixed human brains. This model is part of a neuroanatomical reference system (NeuRef) which enables 3D visualization of the brain and shows the relationship of its components such as anatomical structures, functional fibre tracts and arteries. Sections through the models can be matched with corresponding CT or MR images. This allows the probable localisation of corticospinal fibres on CT or MRI. (orig.) (orig.)

  8. The advantage of the three dimensional computed tomographic (3 D-CT for ensuring accurate bone incision in sagittal split ramus osteotomy

    Directory of Open Access Journals (Sweden)

    Coen Pramono D

    2005-03-01

    Full Text Available Functional and aesthetic dysgnathia surgery requires accurate pre-surgical planning, including the surgical technique to be used related with the difference of anatomical structures amongst individuals. Programs that simulate the surgery become increasingly important. This can be mediated by using a surgical model, conventional x-rays as panoramic, cephalometric projections and another sophisticated method such as a three dimensional computed tomography (3 D-CT. A patient who had undergone double jaw surgeries with difficult anatomical landmarks was presented. In this case the mandible foramens were seen highly relatively related to the sigmoid notches. Therefore, ensuring the bone incisions in sagittal split was presumed to be difficult. A 3D-CT was made and considered to be very helpful in supporting the pre-operative diagnostic.

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  10. Elfin: An algorithm for the computational design of custom three-dimensional structures from modular repeat protein building blocks.

    Science.gov (United States)

    Yeh, Chun-Ting; Brunette, T J; Baker, David; McIntosh-Smith, Simon; Parmeggiani, Fabio

    2018-02-01

    Computational protein design methods have enabled the design of novel protein structures, but they are often still limited to small proteins and symmetric systems. To expand the size of designable proteins while controlling the overall structure, we developed Elfin, a genetic algorithm for the design of novel proteins with custom shapes using structural building blocks derived from experimentally verified repeat proteins. By combining building blocks with compatible interfaces, it is possible to rapidly build non-symmetric large structures (>1000 amino acids) that match three-dimensional geometric descriptions provided by the user. A run time of about 20min on a laptop computer for a 3000 amino acid structure makes Elfin accessible to users with limited computational resources. Protein structures with controlled geometry will allow the systematic study of the effect of spatial arrangement of enzymes and signaling molecules, and provide new scaffolds for functional nanomaterials. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers

    International Nuclear Information System (INIS)

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer pregrain is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex Industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional equations of conservation of mass, momentum, and energy on the tube stile and the proper accounting for the thermal interaction between shell and tube side through the porous-medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient. Three-dimensional analysis of fluid flow with heat transfer tn a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification, it can be used to analyze processes in any heat exchanger or other single-phase engineering applications. Volume I (Equations and Numerics) of this report describes in detail the basic equations, formulation, solution procedures, and models for a phenomena. Volume II (User's Guide and Manual) contains the input instruction, flow charts, sample problems, and descriptions of available options and boundary conditions

  12. Performing three-dimensional neutral particle transport calculations on tera scale computers

    International Nuclear Information System (INIS)

    Woodward, C.S.; Brown, P.N.; Chang, B.; Dorr, M.R.; Hanebutte, U.R.

    1999-01-01

    A scalable, parallel code system to perform neutral particle transport calculations in three dimensions is presented. To utilize the hyper-cluster architecture of emerging tera scale computers, the parallel code successfully combines the MPI message passing and paradigms. The code's capabilities are demonstrated by a shielding calculation containing over 14 billion unknowns. This calculation was accomplished on the IBM SP ''ASCI-Blue-Pacific computer located at Lawrence Livermore National Laboratory (LLNL)

  13. Fluid dynamics of flapping aquatic flight in the bird wrasse: three-dimensional unsteady computations with fin deformation.

    Science.gov (United States)

    Ramamurti, Ravi; Sandberg, William C; Löhner, Rainald; Walker, Jeffrey A; Westneat, Mark W

    2002-10-01

    Many fishes that swim with the paired pectoral fins use fin-stroke parameters that produce thrust force from lift in a mechanism of underwater flight. These locomotor mechanisms are of interest to behavioral biologists, biomechanics researchers and engineers. In the present study, we performed the first three-dimensional unsteady computations of fish swimming with oscillating and deforming fins. The objective of these computations was to investigate the fluid dynamics of force production associated with the flapping aquatic flight of the bird wrasse Gomphosus varius. For this computational work, we used the geometry of the wrasse and its pectoral fin, and previously measured fin kinematics, as the starting points for computational investigation of three-dimensional (3-D) unsteady fluid dynamics. We performed a 3-D steady computation and a complete set of 3-D quasisteady computations for a range of pectoral fin positions and surface velocities. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing was then used to compute the unsteady flow about the wrasse through several complete cycles of pectoral fin oscillation. The shape deformation of the pectoral fin throughout the oscillation was taken from the experimental kinematics. The pressure distribution on the body of the bird wrasse and its pectoral fins was computed and integrated to give body and fin forces which were decomposed into lift and thrust. The velocity field variation on the surface of the wrasse body, on the pectoral fins and in the near-wake was computed throughout the swimming cycle. We compared our computational results for the steady, quasi-steady and unsteady cases with the experimental data on axial and vertical acceleration obtained from the pectoral fin kinematics experiments. These comparisons show that steady state computations are incapable of describing the fluid dynamics of flapping fins. Quasi-steady state computations, with correct incorporation of

  14. 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

  15. Programmable full-adder computations in communicating three-dimensional cell cultures.

    Science.gov (United States)

    Ausländer, David; Ausländer, Simon; Pierrat, Xavier; Hellmann, Leon; Rachid, Leila; Fussenegger, Martin

    2018-01-01

    Synthetic biologists have advanced the design of trigger-inducible gene switches and their assembly into input-programmable circuits that enable engineered human cells to perform arithmetic calculations reminiscent of electronic circuits. By designing a versatile plug-and-play molecular-computation platform, we have engineered nine different cell populations with genetic programs, each of which encodes a defined computational instruction. When assembled into 3D cultures, these engineered cell consortia execute programmable multicellular full-adder logics in response to three trigger compounds.

  16. Nuclear plant operations, maintenance, and configuration management using three-dimensional computer graphics and databases

    International Nuclear Information System (INIS)

    Tutos, N.C.; Reinschmidt, K.F.

    1987-01-01

    Stone and Webster Engineering Corporation has developed the Plant Digital Model concept as a new approach to Configuration Mnagement of nuclear power plants. The Plant Digital Model development is a step-by-step process, based on existing manual procedures and computer applications, and is fully controllable by the plant managers and engineers. The Plant Digital Model is based on IBM computer graphics and relational database management systems, and therefore can be easily integrated with existing plant databases and corporate management-information systems

  17. 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 ...

  18. 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 ...

  19. Three-dimensional measurement of temporal bone by using personal computer

    International Nuclear Information System (INIS)

    Kimura, Hiroki; Murata, Kiyotaka; Isono, Michio; Azuma, Hiroji; Itou, Akihiko

    1996-01-01

    Measurement of anatomical indices in human temporal bone has been reported only sporadically using high resolution CT. We developed a method for measuring such indices by computer assisted processing of images obtained by high resolusion CT. Intensive measurement of distances between all anatomical points in the entire temporal bone structure became possible with this method. (author)

  20. Computational Methods for Inviscid and Viscous Two-and-Three-Dimensional Flow Fields.

    Science.gov (United States)

    1975-01-01

    Difference Equations Over a Network, Watson Sei. Comput. Lab. Report, 19U9. 173- Isaacson, E. and Keller, H. B., Analaysis of Numerical Methods...element method has given a new impulse to the old mathematical theory of multivariate interpolation. We first study the one-dimensional case, which

  1. Three-dimensional Computational Fluid Dynamics Investigation of a Spinning Helicopter Slung Load

    Science.gov (United States)

    Theorn, J. N.; Duque, E. P. N.; Cicolani, L.; Halsey, R.

    2005-01-01

    After performing steady-state Computational Fluid Dynamics (CFD) calculations using OVERFLOW to validate the CFD method against static wind-tunnel data of a box-shaped cargo container, the same setup was used to investigate unsteady flow with a moving body. Results were compared to flight test data previously collected in which the container is spinning.

  2. Computational methods for a three-dimensional model of the petroleum-discovery process

    Science.gov (United States)

    Schuenemeyer, J.H.; Bawiec, W.J.; Drew, L.J.

    1980-01-01

    A discovery-process model devised by Drew, Schuenemeyer, and Root can be used to predict the amount of petroleum to be discovered in a basin from some future level of exploratory effort: the predictions are based on historical drilling and discovery data. Because marginal costs of discovery and production are a function of field size, the model can be used to make estimates of future discoveries within deposit size classes. The modeling approach is a geometric one in which the area searched is a function of the size and shape of the targets being sought. A high correlation is assumed between the surface-projection area of the fields and the volume of petroleum. To predict how much oil remains to be found, the area searched must be computed, and the basin size and discovery efficiency must be estimated. The basin is assumed to be explored randomly rather than by pattern drilling. The model may be used to compute independent estimates of future oil at different depth intervals for a play involving multiple producing horizons. We have written FORTRAN computer programs that are used with Drew, Schuenemeyer, and Root's model to merge the discovery and drilling information and perform the necessary computations to estimate undiscovered petroleum. These program may be modified easily for the estimation of remaining quantities of commodities other than petroleum. ?? 1980.

  3. Comparison of Scrape-off Layer Turbulence in Alcator C-Mod with Three Dimensional Gyrofluid Computations

    International Nuclear Information System (INIS)

    Zweben, S.J.; Scott, B.D.; Terry, J.L.; LaBombard, B.; Hughes, J.W.; Stotler, D.P.

    2009-01-01

    This paper describes quantitative comparisons between turbulence measured in the scrape-off layer (SOL) of Alcator C-Mod (S. Scott, A. Bader, M. Bakhtiari et al., Nucl. Fusion 47, S598 (2007)) and three dimensional computations using electromagnetic gyrofluid equations in a two-dimensional tokamak geometry. These comparisons were made for the outer midplane SOL for a set of inner-wall limited, near-circular Ohmic plasmas. The B field and plasma density were varied to assess gyroradius and collisionality scaling. The poloidal and radial correlation lengths in the experiment and computation agreed to within a factor of 2 and did not vary significantly with either B or density. The radial and poloidal propagation speeds and the frequency spectra and poloidal k-spectra also agreed fairly well. However, the autocorrelation times and relative Da fluctuation levels were higher in the experiment by more than a factor of 2. Possible causes for these disagreements are discussed.

  4. Innovative procedure for computer-assisted genioplasty: three-dimensional cephalometry, rapid-prototyping model and surgical splint.

    Science.gov (United States)

    Olszewski, R; Tranduy, K; Reychler, H

    2010-07-01

    The authors present a new procedure of computer-assisted genioplasty. They determined the anterior, posterior and inferior limits of the chin in relation to the skull and face with the newly developed and validated three-dimensional cephalometric planar analysis (ACRO 3D). Virtual planning of the osteotomy lines was carried out with Mimics (Materialize) software. The authors built a three-dimensional rapid-prototyping multi-position model of the chin area from a medical low-dose CT scan. The transfer of virtual information to the operating room consisted of two elements. First, the titanium plates on the 3D RP model were pre-bent. Second, a surgical guide for the transfer of the osteotomy lines and the positions of the screws to the operating room was manufactured. The authors present the first case of the use of this model on a patient. The postoperative results are promising, and the technique is fast and easy-to-use. More patients are needed for a definitive clinical validation of this procedure. Copyright 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  5. Real-time three-dimensional echocardiographic left ventricular ejection fraction and volumes assessment: comparison with cardiac computed tomography; Comparacao entre a afericao da fracao de ejecao e dos volumes do ventriculo esquerdo, medidos com ecocardiografia tridimensional em tempo real e com tomografia computadorizada ultra-rapida

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Marcelo L.C.; Nomura, Cesar H.; Tranchesi Junior, Bernardino; Oliveira, Wercules A. de; Naccarato, Gustavo; Serpa, Bruna S.; Cury, Alexandre; Passos, Rodrigo B.D.; Nobrega, Marcel V. da; Funari, Marcelo B.G.; Pfefermam, Abhaham; Makdisse, Marcia; Fischer, Claudio H.; Morhy, Samira S., E-mail: luiz766@terra.com.br [Hospital Israelita Albert Einstein, Sao Paulo, SP (Brazil)

    2008-10-15

    Background and objective: Few studies addressed the comparison between real-time 3D echocardiography (RT3DE) and cardiac computed tomography (CCT) concerning left ventricular ejection fraction and volumes assessment. We sought to compare both techniques regarding left ventricle (LV) ejection fraction function and volumes analysis. Methods: we studied by RT3DE (Philips IE 33, And, MA, USA) and by CCT (Toshiba, 64-slice, Otawara, Japan) 41 consecutive patients (29 males, 58 ± 11 yrs). We analysed by both techniques LVEF, LVEDV, LVESV. RT3DE and CCT data were compared by coefficients of determination (r: Pearson), Bland and Altman test and linear regression, 95% CI. Results: RT3DE data: LVEF ranged from 56.7 to 78.9 % (65.3 + 5.7 ); LVEDV ranged from 49.6 to 178.2 (88 + 27.5) mL; LVESV from 11.4 to 78 ( 33.9 + 13.7) mL. CCT data: LVEF ranged from 53 to 86 % (67.3 + 7.9 ); LVEDV ranged from 51 to 186 (106.4 + 30.7) mL; LVESV from 7 to 72 ( 35.1 + 13.8) mL. Correlations relative to RT3DE and CCT were: LVEF (r: 0. 7877, p<0.0001, 95 % CI 0.6327 to 0.8853 ); LVEDV (r:0.7671, p<0.0001, 95 % CI 0.5974 to 0.8745); LVESV (r: 0.8121, p<0.0001, 95 % CI 0.6659 to 0.8957). Conclusions: it was observed adequate correlation between real-time 3D echocardiography and cardiac computed tomography concerning ejection fraction and volumes assessment. (author)

  6. Development and validation of GWHEAD, a three-dimensional groundwater head computer code

    International Nuclear Information System (INIS)

    Beckmeyer, R.R.; Root, R.W.; Routt, K.R.

    1980-03-01

    A computer code has been developed to solve the groundwater flow equation in three dimensions. The code has finite-difference approximations solved by the strongly implicit solution procedure. Input parameters to the code include hydraulic conductivity, specific storage, porosity, accretion (recharge), and initial hydralic head. These parameters may be input as varying spatially. The hydraulic conductivity may be input as isotropic or anisotropic. The boundaries either may permit flow across them or may be impermeable. The code has been used to model leaky confined groundwater conditions and spherical flow to a continuous point sink, both of which have exact analytical solutions. The results generated by the computer code compare well with those of the analytical solutions. The code was designed to be used to model groundwater flow beneath fuel reprocessing and waste storage areas at the Savannah River Plant

  7. Computational experience with a three-dimensional rotary engine combustion model

    Science.gov (United States)

    Raju, M. S.; Willis, E. A.

    1990-04-01

    A new computer code was developed to analyze the chemically reactive flow and spray combustion processes occurring inside a stratified-charge rotary engine. Mathematical and numerical details of the new code were recently described by the present authors. The results are presented of limited, initial computational trials as a first step in a long-term assessment/validation process. The engine configuration studied was chosen to approximate existing rotary engine flow visualization and hot firing test rigs. Typical results include: (1) pressure and temperature histories, (2) torque generated by the nonuniform pressure distribution within the chamber, (3) energy release rates, and (4) various flow-related phenomena. These are discussed and compared with other predictions reported in the literature. The adequacy or need for improvement in the spray/combustion models and the need for incorporating an appropriate turbulence model are also discussed.

  8. IVA3: Computer code for modelling of transient three dimensional three phase flow in complicated geometry

    International Nuclear Information System (INIS)

    Kolev, N.I.

    1991-12-01

    This report describes the input and output ov IVA3 computer code and the procedure how to compile, link, and run the code. The common blocs recorded for restarts files and post processing are described in detail as well as the IVA3 interface for thermodynamic and thermo physical properties. Some recommendations for the input preparation together with some detailed comments on some architectural and functional features of the code are given in order to give some insight of the caused actions by changing some control parameters. (orig.) [de

  9. 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)

  10. Fast and accurate three-dimensional point spread function computation for fluorescence microscopy.

    Science.gov (United States)

    Li, Jizhou; Xue, Feng; Blu, Thierry

    2017-06-01

    The point spread function (PSF) plays a fundamental role in fluorescence microscopy. A realistic and accurately calculated PSF model can significantly improve the performance in 3D deconvolution microscopy and also the localization accuracy in single-molecule microscopy. In this work, we propose a fast and accurate approximation of the Gibson-Lanni model, which has been shown to represent the PSF suitably under a variety of imaging conditions. We express the Kirchhoff's integral in this model as a linear combination of rescaled Bessel functions, thus providing an integral-free way for the calculation. The explicit approximation error in terms of parameters is given numerically. Experiments demonstrate that the proposed approach results in a significantly smaller computational time compared with current state-of-the-art techniques to achieve the same accuracy. This approach can also be extended to other microscopy PSF models.

  11. Computation of Casimir interactions between arbitrary three-dimensional objects with arbitrary material properties

    International Nuclear Information System (INIS)

    Reid, M. T. Homer; White, Jacob; Johnson, Steven G.

    2011-01-01

    We extend a recently introduced method for computing Casimir forces between arbitrarily shaped metallic objects [M. T. H. Reid et al., Phys. Rev. Lett. 103 040401 (2009)] to allow treatment of objects with arbitrary material properties, including imperfect conductors, dielectrics, and magnetic materials. Our original method considered electric currents on the surfaces of the interacting objects; the extended method considers both electric and magnetic surface current distributions, and obtains the Casimir energy of a configuration of objects in terms of the interactions of these effective surface currents. Using this new technique, we present the first predictions of Casimir interactions in several experimentally relevant geometries that would be difficult to treat with any existing method. In particular, we investigate Casimir interactions between dielectric nanodisks embedded in a dielectric fluid; we identify the threshold surface-surface separation at which finite-size effects become relevant, and we map the rotational energy landscape of bound nanoparticle diclusters.

  12. Time evolution of a quenched binary alloy: computer simulation of a three-dimensional model system

    International Nuclear Information System (INIS)

    Marro, J.; Bortz, A.B.; Kalos, M.H.; Lebowitz, J.L.; Sur, A.

    1976-01-01

    Results are presented of computer simulation of the time evolution for a model of a binary alloy, such as ZnAl, following quenching. The model system is a simple cubic lattice the sites of which are occupied either by A or B particles. There is a nearest neighbor interaction favoring segregation into an A rich and a B rich phase at low temperatures, T less than T/sub c/. Starting from a random configuration, T much greater than T/sub c/, the system is quenched to and evolves at a temperature T less than T/sub c/. The evolution takes place through exchanges between A and B atoms on nearest neighbor sites. The probability of such an exchange is assumed proportional to e/sup -βΔU/ [1 + e/sup -βΔU/] -1 where β = (k/sub B/T) -1 and ΔU is the change in energy resulting from the exchange. In the simulations either a 30 x 30 x 30 or a 50 x 50 x 50 lattice is used with various fractions of the sites occupied by A particles. The evolution of the Fourier transform of the spherically averaged structure function S(k,t), the energy, and the cluster distribution were computed. Comparison is made with various theories of this process and with some experiments. It is found in particular that the results disagree with the predictions of the linearized Cahn-Hilliard theory of spinodal decomposition. The qualitative form of the results appear to be unaffected if the change in the positions of the atoms takes place via a vacancy mechanism rather than through direct exchanges

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

    Medline Plus

    Full Text Available ... planes, and can even generate three-dimensional images. These images can be viewed on a computer monitor, ... diabetes, kidney disease or thyroid problems. Any of these conditions may influence the decision on whether contrast ...

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

    Medline Plus

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

  15. Consequences of fiducial marker error on three-dimensional computer animation of the temporomandibular joint

    Science.gov (United States)

    Leader, J. Ken, III; Boston, J. Robert; Rudy, Thomas E.; Greco, Carol M.; Zaki, Hussein S.

    2001-05-01

    Jaw motion has been used to diagnose jaw pain patients, and we have developed a 3D computer animation technique to study jaw motion. A customized dental clutch was worn during motion, and its consistent and rigid placement was a concern. The experimental protocol involved mandibular movements (vertical opening) and MR imaging. The clutch contained three motion markers used to collect kinematic data and four MR markers used as fiducial markers in the MR images. Fiducial marker misplacement was mimicked by analytically perturbing the position of the MR markers +/- 2, +/- 4, and +/- 6 degrees in the three anatomical planes. The percent difference between the original and perturbed MR marker position was calculated for kinematic parameters. The maximum difference across all perturbations for axial rotation, coronal rotation, sagittal rotation, axial translation, coronal translation, and sagittal translation were 176.85%, 191.84%, 0.64%, 9.76%, 80.75%, and 8.30%, respectively, for perturbing all MR markers, and 86.47%, 93.44%, 0.23%, 7.08%, 42.64%, and 13.64%, respectively, for perturbing one MR marker. The parameters representing movement in the sagittal plane, the dominant plane in vertical opening, were determined to be reasonably robust, while secondary movements in the axial and coronal planes were not considered robust.

  16. Three-dimensional computer-aided human factors engineering analysis of a grafting robot.

    Science.gov (United States)

    Chiu, Y C; Chen, S; Wu, G J; Lin, Y H

    2012-07-01

    The objective of this research was to conduct a human factors engineering analysis of a grafting robot design using computer-aided 3D simulation technology. A prototype tubing-type grafting robot for fruits and vegetables was the subject of a series of case studies. To facilitate the incorporation of human models into the operating environment of the grafting robot, I-DEAS graphic software was applied to establish individual models of the grafting robot in line with Jack ergonomic analysis. Six human models (95th percentile, 50th percentile, and 5th percentile by height for both males and females) were employed to simulate the operating conditions and working postures in a real operating environment. The lower back and upper limb stresses of the operators were analyzed using the lower back analysis (LBA) and rapid upper limb assessment (RULA) functions in Jack. The experimental results showed that if a leg space is introduced under the robot, the operator can sit closer to the robot, which reduces the operator's level of lower back and upper limbs stress. The proper environmental layout for Taiwanese operators for minimum levels of lower back and upper limb stress are to set the grafting operation at 23.2 cm away from the operator at a height of 85 cm and with 45 cm between the rootstock and scion units.

  17. Development of an aeroelastic code based on three-dimensional viscous–inviscid method for wind turbine computations

    DEFF Research Database (Denmark)

    Sessarego, Matias; Ramos García, Néstor; Sørensen, Jens Nørkær

    2017-01-01

    Aerodynamic and structural dynamic performance analysis of modern wind turbines are routinely estimated in the wind energy field using computational tools known as aeroelastic codes. Most aeroelastic codes use the blade element momentum (BEM) technique to model the rotor aerodynamics and a modal......, multi-body or the finite-element approach to model the turbine structural dynamics. The present work describes the development of a novel aeroelastic code that combines a three-dimensional viscous–inviscid interactive method, method for interactive rotor aerodynamic simulations (MIRAS...... Code Comparison Collaboration Project. Simulation tests consist of steady wind inflow conditions with different combinations of yaw error, wind shear, tower shadow and turbine-elastic modeling. Turbulent inflow created by using a Mann box is also considered. MIRAS-FLEX results, such as blade tip...

  18. Computed Tomography (CT) -- Head

    Medline Plus

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

  19. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  20. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... other medical conditions and whether you have a history of heart disease, asthma, diabetes, kidney disease or ... Neck Cancer X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to Computed Tomography (CT) - ...

  1. Computed Tomography (CT) -- Head

    Medline Plus

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

  2. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... white on the x-ray; soft tissue, such as organs like the heart or liver, shows up ...

  3. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... of the Sinuses? Computed tomography, more commonly known as a CT or CAT scan, is a diagnostic ... white on the x-ray; soft tissue, such as organs like the heart or liver, shows up ...

  4. Computed Tomography (CT) -- Head

    Medline Plus

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

  5. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  6. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Computed tomography (CT) of the sinuses uses special x-ray equipment to evaluate the paranasal sinus cavities – hollow, air-filled spaces within the bones of the face surrounding the ...

  7. 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)

  8. Computational modeling for prediction of the shear stress of three-dimensional isotropic and aligned fiber networks.

    Science.gov (United States)

    Park, Seungman

    2017-09-01

    Interstitial flow (IF) is a creeping flow through the interstitial space of the extracellular matrix (ECM). IF plays a key role in diverse biological functions, such as tissue homeostasis, cell function and behavior. Currently, most studies that have characterized IF have focused on the permeability of ECM or shear stress distribution on the cells, but less is known about the prediction of shear stress on the individual fibers or fiber networks despite its significance in the alignment of matrix fibers and cells observed in fibrotic or wound tissues. In this study, I developed a computational model to predict shear stress for different structured fibrous networks. To generate isotropic models, a random growth algorithm and a second-order orientation tensor were employed. Then, a three-dimensional (3D) solid model was created using computer-aided design (CAD) software for the aligned models (i.e., parallel, perpendicular and cubic models). Subsequently, a tetrahedral unstructured mesh was generated and flow solutions were calculated by solving equations for mass and momentum conservation for all models. Through the flow solutions, I estimated permeability using Darcy's law. Average shear stress (ASS) on the fibers was calculated by averaging the wall shear stress of the fibers. By using nonlinear surface fitting of permeability, viscosity, velocity, porosity and ASS, I devised new computational models. Overall, the developed models showed that higher porosity induced higher permeability, as previous empirical and theoretical models have shown. For comparison of the permeability, the present computational models were matched well with previous models, which justify our computational approach. ASS tended to increase linearly with respect to inlet velocity and dynamic viscosity, whereas permeability was almost the same. Finally, the developed model nicely predicted the ASS values that had been directly estimated from computational fluid dynamics (CFD). The present

  9. Three-Dimensional X-Ray Photoelectron Tomography on the Nanoscale: Limits of Data Processing by Principal Component Analysis

    DEFF Research Database (Denmark)

    Hajati, S.; Walton, J.; Tougaard, S.

    2013-01-01

    In a previous article, we studied the influence of spectral noise on a new method for three-dimensional X-ray photoelectron spectroscopy (3D XPS) imaging, which is based on analysis of the XPS peak shape [Hajati, S., Tougaard, S., Walton, J. & Fairley, N. (2008). Surf Sci 602, 3064-3070]. Here, we...... study in more detail the influence of noise reduction by principal component analysis (PCA) on 3D XPS images of carbon contamination of a patterned oxidized silicon sample and on 3D XPS images of Ag covered by a nanoscale patterned octadiene layer. PCA is very efficient for noise reduction, and using...... acquisition time. A small additional amount of information is obtained by using up to five PCA factors, but due to the increased noise level, this information can only be extracted if the intensity of the start and end points for each spectrum are obtained as averages over several energy points....

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

    Science.gov (United States)

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

    2015-01-01

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

  11. Motion artifacts in computed tomography

    International Nuclear Information System (INIS)

    Yang, C.K.

    1979-01-01

    In the year 1972, the first Computed Tomography Scanner (or CT) was introduced and caused a revolution in the field of Diagnostic Radiology. A tomogram is a cross-sectional image of a three-dimensional object obtained through non-invasive measurements. The image that is presented is very similar to what would be seen if a thin cross-sectional slice of the patient was examined. In Computed Tomography, x-rays are passed through the body of a patient in many different directions and their attenuation is detected. By using some mathematical theorems, the attenuation information can be converted into the density of the patient along the x-ray path. Combined with modern sophisticated computer signal processing technology, a cross-sectional image can be generated and displayed on a TV monitor. Usually a good CT image relies on the patient not moving during the x-ray scanning. However, for some unconscious or severely ill patients, this is very difficult to achieve. Thus, the motion during the scan causes the so-called motion artifacts which distort the displayed image and sometimes these motion artifacts make diagnosis impossible. Today, to remove or avoid motion artifacts is one of the major efforts in developing new scanner systems. In this thesis, a better understanding of the motion artifacts problem in CT scaning is gained through computer simulations, real scanner experiments and theoretical analyses. The methods by which the distorted image can be improved are simulated also. In particular, it is assumed that perfect knowledge of the patient motion is known since this represents the theoretical limit on how well the distorted image can be improved

  12. [COMPUTER ASSISTED DESIGN AND ELECTRON BEAMMELTING RAPID PROTOTYPING METAL THREE-DIMENSIONAL PRINTING TECHNOLOGY FOR PREPARATION OF INDIVIDUALIZED FEMORAL PROSTHESIS].

    Science.gov (United States)

    Liu, Hongwei; Weng, Yiping; Zhang, Yunkun; Xu, Nanwei; Tong, Jing; Wang, Caimei

    2015-09-01

    To study the feasibility of preparation of the individualized femoral prosthesis through computer assisted design and electron beammelting rapid prototyping (EBM-RP) metal three-dimensional (3D) printing technology. One adult male left femur specimen was used for scanning with 64-slice spiral CT; tomographic image data were imported into Mimics15.0 software to reconstruct femoral 3D model, then the 3D model of individualized femoral prosthesis was designed through UG8.0 software. Finally the 3D model data were imported into EBM-RP metal 3D printer to print the individualized sleeve. According to the 3D model of individualized prosthesis, customized sleeve was successfully prepared through the EBM-RP metal 3D printing technology, assembled with the standard handle component of SR modular femoral prosthesis to make the individualized femoral prosthesis. Customized femoral prosthesis accurately matching with metaphyseal cavity can be designed through the thin slice CT scanning and computer assisted design technology. Titanium alloy personalized prosthesis with complex 3D shape, pore surface, and good matching with metaphyseal cavity can be manufactured by the technology of EBM-RP metal 3D printing, and the technology has convenient, rapid, and accurate advantages.

  13. Three-dimensional coupled Monte Carlo-discrete ordinates computational scheme for shielding calculations of large and complex nuclear facilities

    International Nuclear Information System (INIS)

    Chen, Y.; Fischer, U.

    2005-01-01

    Shielding calculations of advanced nuclear facilities such as accelerator based neutron sources or fusion devices of the tokamak type are complicated due to their complex geometries and their large dimensions, including bulk shields of several meters thickness. While the complexity of the geometry in the shielding calculation can be hardly handled by the discrete ordinates method, the deep penetration of radiation through bulk shields is a severe challenge for the Monte Carlo particle transport technique. This work proposes a dedicated computational scheme for coupled Monte Carlo-Discrete Ordinates transport calculations to handle this kind of shielding problems. The Monte Carlo technique is used to simulate the particle generation and transport in the target region with both complex geometry and reaction physics, and the discrete ordinates method is used to treat the deep penetration problem in the bulk shield. The coupling scheme has been implemented in a program system by loosely integrating the Monte Carlo transport code MCNP, the three-dimensional discrete ordinates code TORT and a newly developed coupling interface program for mapping process. Test calculations were performed with comparison to MCNP solutions. Satisfactory agreements were obtained between these two approaches. The program system has been chosen to treat the complicated shielding problem of the accelerator-based IFMIF neutron source. The successful application demonstrates that coupling scheme with the program system is a useful computational tool for the shielding analysis of complex and large nuclear facilities. (authors)

  14. Computational study of effects of tension imbalance on phonation in a three-dimensional tubular larynx model.

    Science.gov (United States)

    Xue, Qian; Zheng, Xudong; Mittal, Rajat; Bielamowicz, Steven

    2014-07-01

    The present study explores the use of a continuum-based computational model to investigate the effect of left-right tension imbalance on vocal fold (VF) vibrations and glottal aerodynamics, as well as its implication on phonation. The study allows us to gain new insights into the underlying physical mechanism of irregularities induced by VF tension imbalance associated with unilateral cricothyroid muscle paralysis. A three-dimensional simulation of glottal flow and VF dynamics in a tubular laryngeal model with tension imbalance was conducted by using a coupled flow-structure interaction computational model. Tension imbalance was modeled by reducing by 20% the Young's modulus of one of the VFs, while holding VF length constant. Effects of tension imbalance on vibratory characteristic of the VFs and on the time-varying properties of glottal airflow as well as the aerodynamic energy transfer are comprehensively analyzed. The analysis demonstrates that the continuum-based biomechanical model can provide a good description of phonatory dynamics in tension imbalance conditions. It is found that although 20% tension imbalance does not have noticeable effects on the fundamental frequency, it does lead to a larger glottal flow leakage and asymmetric vibrations of the two VFs. A detailed analysis of the energy transfer suggests that the majority of the energy is consumed by the lateral motion of the VFs and the net energy transferred to the softer fold is less than the one transferred to the normal fold. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  15. Volumetric Analysis of Alveolar Bone Defect Using Three-Dimensional-Printed Models Versus Computer-Aided Engineering.

    Science.gov (United States)

    Du, Fengzhou; Li, Binghang; Yin, Ningbei; Cao, Yilin; Wang, Yongqian

    2017-03-01

    Knowing the volume of a graft is essential in repairing alveolar bone defects. This study investigates the 2 advanced preoperative volume measurement methods: three-dimensional (3D) printing and computer-aided engineering (CAE). Ten unilateral alveolar cleft patients were enrolled in this study. Their computed tomographic data were sent to 3D printing and CAE software. A simulated graft was used on the 3D-printed model, and the graft volume was measured by water displacement. The volume calculated by CAE software used mirror-reverses technique. The authors compared the actual volumes of the simulated grafts with the CAE software-derived volumes. The average volume of the simulated bone grafts by 3D-printed models was 1.52 mL, higher than the mean volume of 1.47 calculated by CAE software. The difference between the 2 volumes was from -0.18 to 0.42 mL. The paired Student t test showed no statistically significant difference between the volumes derived from the 2 methods. This study demonstrated that the mirror-reversed technique by CAE software is as accurate as the simulated operation on 3D-printed models in unilateral alveolar cleft patients. These findings further validate the use of 3D printing and CAE technique in alveolar defect repairing.

  16. The value of unenhanced multi-detector computed tomography ...

    African Journals Online (AJOL)

    Introduction: Unenhanced computed tomography (CT) is used to detect urinary tract calculi with high accuracy. The development of multi-detector CT (MDCT) allows reconstructions in coronal, sagittal and oblique directions. Objective: To compare MDCT with three-dimensional (3D) ultrasound (US) imaging in evaluating ...

  17. Quadcopter control in three-dimensional space using a noninvasive motor imagery-based brain-computer interface

    Science.gov (United States)

    LaFleur, Karl; Cassady, Kaitlin; Doud, Alexander; Shades, Kaleb; Rogin, Eitan; He, Bin

    2013-08-01

    Objective. At the balanced intersection of human and machine adaptation is found the optimally functioning brain-computer interface (BCI). In this study, we report a novel experiment of BCI controlling a robotic quadcopter in three-dimensional (3D) physical space using noninvasive scalp electroencephalogram (EEG) in human subjects. We then quantify the performance of this system using metrics suitable for asynchronous BCI. Lastly, we examine the impact that the operation of a real world device has on subjects' control in comparison to a 2D virtual cursor task. Approach. Five human subjects were trained to modulate their sensorimotor rhythms to control an AR Drone navigating a 3D physical space. Visual feedback was provided via a forward facing camera on the hull of the drone. Main results. Individual subjects were able to accurately acquire up to 90.5% of all valid targets presented while travelling at an average straight-line speed of 0.69 m s-1. Significance. Freely exploring and interacting with the world around us is a crucial element of autonomy that is lost in the context of neurodegenerative disease. Brain-computer interfaces are systems that aim to restore or enhance a user's ability to interact with the environment via a computer and through the use of only thought. We demonstrate for the first time the ability to control a flying robot in 3D physical space using noninvasive scalp recorded EEG in humans. Our work indicates the potential of noninvasive EEG-based BCI systems for accomplish complex control in 3D physical space. The present study may serve as a framework for the investigation of multidimensional noninvasive BCI control in a physical environment using telepresence robotics.

  18. ERATO - a computer program for the calculation of induced eddy-currents in three-dimensional conductive structures

    International Nuclear Information System (INIS)

    Benner, J.

    1985-10-01

    The computer code ERATO is used for the calculation of eddy-currents in three-dimensional conductive structures and their secondary magnetic field. ERATO is a revised version of the code FEDIFF, developed at IPP Garching. For the calculation the Finite-Element-Network (FEN) method is used, where the structure is simulated by an equivalent electric network. In the ERATO-code, the calculation of the finite-element discretization, the eddy-current analysis, and the final evaluation of the results are done in separate programs. So the eddy-current analysis as the central step is perfectly independent of a special geometry. For the finite-element discretization there are two so called preprocessors, which treat a torus-segment and a rectangular, flat plate. For the final evaluation postprocessors are used, by which the current-distributions can be printed and plotted. In the report, the theoretical foundation of the FEN-Method is discussed, the structure and the application of the programs (preprocessors, analysis-program, postprocessors, supporting programs) are shown, and two examples for calculations are presented. (orig.) [de

  19. RAMONA-4B a computer code with three-dimensional neutron kinetics for BWR and SBWR system transient - user's manual

    International Nuclear Information System (INIS)

    Rohatgi, U.S.; Cheng, H.S.; Khan, H.J.; Mallen, A.N.; Neymotin, L.Y.

    1998-03-01

    This document is the User's Manual for the Boiling Water Reactor (BWR), and Simplified Boiling Water Reactor (SBWR) systems transient code RAMONA-4B. The code uses a three-dimensional neutron-kinetics model coupled with a multichannel, nonequilibrium, drift-flux, phase-flow model of the thermal hydraulics of the reactor vessel. The code is designed to analyze a wide spectrum of BWR core and system transients. Chapter 1 gives an overview of the code's capabilities and limitations; Chapter 2 describes the code's structure, lists major subroutines, and discusses the computer requirements. Chapter 3 is on code, auxillary codes, and instructions for running RAMONA-4B on Sun SPARC and IBM Workstations. Chapter 4 contains component descriptions and detailed card-by-card input instructions. Chapter 5 provides samples of the tabulated output for the steady-state and transient calculations and discusses the plotting procedures for the steady-state and transient calculations. Three appendices contain important user and programmer information: lists of plot variables (Appendix A) listings of input deck for sample problem (Appendix B), and a description of the plotting program PAD (Appendix C). 24 refs., 18 figs., 11 tabs

  20. Regularity criterion for solutions of the three-dimensional Cahn-Hilliard-Navier-Stokes equations and associated computations.

    Science.gov (United States)

    Gibbon, John D; Pal, Nairita; Gupta, Anupam; Pandit, Rahul

    2016-12-01

    We consider the three-dimensional (3D) Cahn-Hilliard equations coupled to, and driven by, the forced, incompressible 3D Navier-Stokes equations. The combination, known as the Cahn-Hilliard-Navier-Stokes (CHNS) equations, is used in statistical mechanics to model the motion of a binary fluid. The potential development of singularities (blow-up) in the contours of the order parameter ϕ is an open problem. To address this we have proved a theorem that closely mimics the Beale-Kato-Majda theorem for the 3D incompressible Euler equations [J. T. Beale, T. Kato, and A. J. Majda, Commun. Math. Phys. 94, 61 (1984)CMPHAY0010-361610.1007/BF01212349]. By taking an L^{∞} norm of the energy of the full binary system, designated as E_{∞}, we have shown that ∫_{0}^{t}E_{∞}(τ)dτ governs the regularity of solutions of the full 3D system. Our direct numerical simulations (DNSs) of the 3D CHNS equations for (a) a gravity-driven Rayleigh Taylor instability and (b) a constant-energy-injection forcing, with 128^{3} to 512^{3} collocation points and over the duration of our DNSs confirm that E_{∞} remains bounded as far as our computations allow.

  1. Computational Fluid Dynamics Modeling Three-Dimensional Unsteady Turbulent Flow and Excitation Force in Partial Admission Air Turbine

    Directory of Open Access Journals (Sweden)

    Yonghui Xie

    2013-01-01

    Full Text Available Air turbines are widely used to convert kinetic energy into power output in power engineering. The unsteady performance of air turbines with partial admission not only influences the aerodynamic performance and thermodynamic efficiency of turbine but also generates strong excitation force on blades to impair the turbine safely operating. Based on three-dimensional viscous compressible Navier-stokes equations, the present study employs RNG (Renormalization group k-ε turbulence model with finite volume discretization on air turbine with partial admission. Numerical models of four different admission rates with full annulus are built and analyzed via CFD (computational fluid dynamics modeling unsteady flows. Results indicate that the unsteady time-averaged isentropic efficiency is lower than the steady isentropic efficiency, and this difference rises as unsteady isentropic efficiency fluctuates stronger when the admission rate is reduced. The rotor axial and tangential forces with time are provided for all four admission rates. The low frequency excitation forces generated by partial admission are extraordinarily higher than the high frequency excitation forces by stator wakes.

  2. Three-dimensional seismic velocity structure of Mauna Loa and Kilauea volcanoes in Hawaii from local seismic tomography

    Science.gov (United States)

    Lin, Guoqing; Shearer, Peter M.; Matoza, Robin S.; Okubo, Paul G.; Amelung, Falk

    2016-01-01

    We present a new three-dimensional seismic velocity model of the crustal and upper mantle structure for Mauna Loa and Kilauea volcanoes in Hawaii. Our model is derived from the first-arrival times of the compressional and shear waves from about 53,000 events on and near the Island of Hawaii between 1992 and 2009 recorded by the Hawaiian Volcano Observatory stations. The Vp model generally agrees with previous studies, showing high-velocity anomalies near the calderas and rift zones and low-velocity anomalies in the fault systems. The most significant difference from previous models is in Vp/Vs structure. The high-Vp and high-Vp/Vs anomalies below Mauna Loa caldera are interpreted as mafic magmatic cumulates. The observed low-Vp and high-Vp/Vs bodies in the Kaoiki seismic zone between 5 and 15 km depth are attributed to the underlying volcaniclastic sediments. The high-Vp and moderate- to low-Vp/Vs anomalies beneath Kilauea caldera can be explained by a combination of different mafic compositions, likely to be olivine-rich gabbro and dunite. The systematically low-Vp and low-Vp/Vs bodies in the southeast flank of Kilauea may be caused by the presence of volatiles. Another difference between this study and previous ones is the improved Vp model resolution in deeper layers, owing to the inclusion of events with large epicentral distances. The new velocity model is used to relocate the seismicity of Mauna Loa and Kilauea for improved absolute locations and ultimately to develop a high-precision earthquake catalog using waveform cross-correlation data.

  3. Two- and three-dimensional topographic analysis of pathologically myopic eyes with dome-shaped macula and inferior staphyloma by spectral domain optical coherence tomography.

    Science.gov (United States)

    García-Ben, Antonio; Kamal-Salah, Radua; García-Basterra, Ignacio; Gonzalez Gómez, Ana; Morillo Sanchez, María José; García-Campos, Jose Manuel

    2017-05-01

    To investigate the posterior anatomical structure of pathologically myopic eyes with dome-shaped macula and inferior staphyloma using spectral domain optical coherence tomography (SD-OCT). Our database of 260 pathologically myopic eyes was analyzed retrospectively to identify patients with dome-shaped macula and inferior staphyloma. All patients underwent vertical and horizontal SD-OCT scans across the central fovea, with three-dimensional macular map reconstruction. Best-corrected visual acuity, axial length, and choroidal thickness measurements were recorded. The macular bulge height was also analyzed in eyes with dome-shaped macula. In the three-dimensional images, the symmetry and orientation of the main plane of the inward incurvation of the macula were examined. Twenty-eight (10.7%) of the 260 pathologically myopic eyes had dome-shaped macula of one of three different types: a round radially symmetrical dome (eight eyes, 28.5%), a horizontal axially symmetrical oval-shaped dome (15 eyes, 53.5%), or a vertical axially symmetrical oval-shaped dome (five eyes, 17.8%). The macular bulge height was significantly greater in horizontal oval-shaped dome eyes (p = 0.01, for each comparison). Inferior posterior staphylomas were observed in ten (3.8%) of the 260 pathologically myopic eyes with asymmetrical macular bends. Vertical and horizontal OCT sectional scanning in combination with three-dimensional macular map reconstruction provides important information for understanding the posterior anatomical structure of dome-shaped macula and inferior staphyloma in pathologically myopic eyes.

  4. High-resolution computer-generated reflection holograms with three-dimensional effects written directly on a silicon surface by a femtosecond laser.

    Science.gov (United States)

    Wædegaard, Kristian J; Balling, Peter

    2011-02-14

    An infrared femtosecond laser has been used to write computer-generated holograms directly on a silicon surface. The high resolution offered by short-pulse laser ablation is employed to write highly detailed holograms with resolution up to 111 kpixels/mm2. It is demonstrated how three-dimensional effects can be realized in computer-generated holograms. Three-dimensional effects are visualized as a relative motion between different parts of the holographic reconstruction, when the hologram is moved relative to the reconstructing laser beam. Potential security applications are briefly discussed.

  5. An easy to produce and economical three-dimensional brain phantom for stereotactic computed tomographic-guided brain biopsy training in the dog.

    Science.gov (United States)

    Sidhu, Deepinder S; Ruth, Jeffrey D; Lambert, Gregory; Rossmeisl, John H

    2017-07-01

    To develop and validate a three-dimensional (3D) brain phantom that can be incorporated into existing stereotactic headframes to simulate stereotactic brain biopsy (SBB) and train veterinary surgeons. Experimental study. Canine brain phantoms were fabricated from osteological skull specimens, agarose brain parenchyma, and cheddar and mozzarella cheese molds (simulating meningiomas and gliomas). The neuroradiologic and viscoelastic properties of phantoms were quantified with computed tomography (CT) and oscillatory compression tests, respectively. Phantoms were validated by experienced and novice operators performing SBB on phantoms containing randomly placed, focal targets. Target yield and needle placement error (NPE) were compared between operators. Phantoms were produced in brain parenchyma, and contrast-enhancing tumors of meningeal and glial origin, respectively. The complex moduli of the agarose and cheeses were comparable to the viscoelastic properties of in vivo brain tissues and brain tumors. The overall diagnostic yield of SBB was 88%. Although NPE did not differ between novice (median 3.68 mm; range, 1.46-14.54 mm) and experienced surgeons (median 1.17 mm, range, 0.78-1.58 mm), our results support the relevance of the learning curve associated with the SBB procedure. This 3D phantom replicates anatomical, CT, and tactile features of brain tissues and tumors and can be used to develop the technical skills required to perform SBB. © 2017 The American College of Veterinary Surgeons.

  6. Three-dimensional bone-free computed tomographic angiography of aneurysms near the skull base using a new bone-removal application

    International Nuclear Information System (INIS)

    Tomura, Noriaki; Otani, Takahiro; Sakuma, Ikuo; Takahashi, Satoshi; Nishii, Toshiaki; Watarai, Jiro

    2009-01-01

    Bone elimination is needed for computed tomography angiography (CTA) because bone structures obscure aneurysms located at the skull base. The purpose of our study was to evaluate the efficacy of three-dimensional (3D)-CTA using an application for bone elimination. A total of 27 patients with 32 angiographically confirmed aneurysms near the skull base were investigated. The 3D maximum intensity projection (MIP) images were initially obtained using the application. Further postprocessing was performed to obtain the MIP and volume-rendered (VR) images. The quality of the initial MIP images by the application was analyzed. Visualization of aneurysms after further processing was also reviewed. The initial MIP images by the application showed almost bone-free images in 23 of the 27 patients. In 8 patients, the image of the internal carotid artery (ICA) was segmentally removed in the initial MIP images by the application. Further postprocessing was able to recover all loss of the ICA image in these eight patients. For visualizing aneurysms and their necks, VR images with the application were significantly superior to VR images without the application. The application for bone elimination allows fast, selective elimination of bony structures and can improve the interpretation of aneurysms near the skull base. (author)

  7. Computed Tomography (CT) -- Head

    Medline Plus

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

  8. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  9. Computed Tomography (CT) -- Sinuses

    Medline Plus

    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  10. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Share your patient story here Images × Image Gallery Patient undergoing computed tomography (CT) scan. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. Related ...

  11. Computed tomography in traumatology

    International Nuclear Information System (INIS)

    Heller, M.; Jend, H.H.

    1986-01-01

    This volume offers a critical review and assessment of new avenues opened up by computed tomography in traumatology. Over 200 illustrations, including numerous CT scans, aid the physician engaged emergency care and postoperative treatment of accident victims. Technical prerequisites, special techniques of investigation, pathomorphology of organ changes conditioned by trauma, diagnostic leading symptoms and signs, and diagnostics of iatrogenic injuries and lesions are presented

  12. Computed tomography system

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  13. Chest computed tomography

    DEFF Research Database (Denmark)

    Loeve, Martine; Krestin, Gabriel P.; Rosenfeld, Margaret

    2013-01-01

    are not suitable to study CF lung disease in young children. Chest computed tomography (CT) holds great promise for use as a sensitive surrogate endpoint in CF. A large body of evidence has been produced to validate the use of chest CT as primary endpoint to study CF lung disease. However, before chest CT can...

  14. Computed Tomography (CT) -- Head

    Medline Plus

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

  15. Computed Tomography (CT) -- Sinuses

    Medline Plus

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

  16. Computed tomography for radiographers

    International Nuclear Information System (INIS)

    Brooker, M.J.

    1986-01-01

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

  17. SEISMIC SIMULATIONS USING PARALLEL COMPUTING AND THREE-DIMENSIONAL EARTH MODELS TO IMPROVE NUCLEAR EXPLOSION PHENOMENOLOGY AND MONITORING

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A; Matzel, E; Pasyanos, M; Petersson, A; Sjogreen, B; Bono, C; Vorobiev, O; Antoun, T; Walter, W; Myers, S; Lomov, I

    2008-07-07

    The development of accurate numerical methods to simulate wave propagation in three-dimensional (3D) earth models and advances in computational power offer exciting possibilities for modeling the motions excited by underground nuclear explosions. This presentation will describe recent work to use new numerical techniques and parallel computing to model earthquakes and underground explosions to improve understanding of the wave excitation at the source and path-propagation effects. Firstly, we are using the spectral element method (SEM, SPECFEM3D code of Komatitsch and Tromp, 2002) to model earthquakes and explosions at regional distances using available 3D models. SPECFEM3D simulates anelastic wave propagation in fully 3D earth models in spherical geometry with the ability to account for free surface topography, anisotropy, ellipticity, rotation and gravity. Results show in many cases that 3D models are able to reproduce features of the observed seismograms that arise from path-propagation effects (e.g. enhanced surface wave dispersion, refraction, amplitude variations from focusing and defocusing, tangential component energy from isotropic sources). We are currently investigating the ability of different 3D models to predict path-specific seismograms as a function of frequency. A number of models developed using a variety of methodologies are available for testing. These include the WENA/Unified model of Eurasia (e.g. Pasyanos et al 2004), the global CUB 2.0 model (Shapiro and Ritzwoller, 2002), the partitioned waveform model for the Mediterranean (van der Lee et al., 2007) and stochastic models of the Yellow Sea Korean Peninsula region (Pasyanos et al., 2006). Secondly, we are extending our Cartesian anelastic finite difference code (WPP of Nilsson et al., 2007) to model the effects of free-surface topography. WPP models anelastic wave propagation in fully 3D earth models using mesh refinement to increase computational speed and improve memory efficiency. Thirdly

  18. Validation of two-dimensional and three-dimensional measurements of subpleural alveolar size parameters by optical coherence tomography

    Science.gov (United States)

    Unglert, Carolin I.; Warger, William C.; Hostens, Jeroen; Namati, Eman; Birngruber, Reginald; Bouma, Brett E.; Tearney, Guillermo J.

    2012-12-01

    Optical coherence tomography (OCT) has been increasingly used for imaging pulmonary alveoli. Only a few studies, however, have quantified individual alveolar areas, and the validity of alveolar volumes represented within OCT images has not been shown. To validate quantitative measurements of alveoli from OCT images, we compared the cross-sectional area, perimeter, volume, and surface area of matched subpleural alveoli from microcomputed tomography (micro-CT) and OCT images of fixed air-filled swine samples. The relative change in size between different alveoli was extremely well correlated (r>0.9, Pvolume), and 25% (surface area) on average. We hypothesized that the differences resulted from refraction at the tissue-air interfaces and developed a ray-tracing model that approximates the reconstructed alveolar size within OCT images. Using this model and OCT measurements of the refractive index for lung tissue (1.41 for fresh, 1.53 for fixed), we derived equations to obtain absolute size measurements of superellipse and circular alveoli with the use of predictive correction factors. These methods and results should enable the quantification of alveolar sizes from OCT images in vivo.

  19. Real-time three-dimensional imaging of epidermal splitting and removal by high-definition optical coherence tomography

    DEFF Research Database (Denmark)

    Boone, Marc; Draye, Jean Pierre; Verween, Gunther

    2014-01-01

    While real-time 3-D evaluation of human skin constructs is needed, only 2-D non-invasive imaging techniques are available. The aim of this paper is to evaluate the potential of high-definition optical coherence tomography (HD-OCT) for real-time 3-D assessment of the epidermal splitting and decell......While real-time 3-D evaluation of human skin constructs is needed, only 2-D non-invasive imaging techniques are available. The aim of this paper is to evaluate the potential of high-definition optical coherence tomography (HD-OCT) for real-time 3-D assessment of the epidermal splitting...... before and after incubation. Real-time 3-D HD-OCT assessment was compared with 2-D en face assessment by reflectance confocal microscopy (RCM). (Immuno) histopathology was used as control. HD-OCT imaging allowed real-time 3-D visualization of the impact of selected agents on epidermal splitting, dermo......-epidermal junction, dermal architecture, vascular spaces and cellularity. RCM has a better resolution (1 μm) than HD-OCT (3 μm), permitting differentiation of different collagen fibres, but HD-OCT imaging has deeper penetration (570 μm) than RCM imaging (200 μm). Dispase II and NaCl treatments were found...

  20. Three-dimensional imaging modalities in endodontics

    Science.gov (United States)

    Mao, Teresa

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337

  1. Three-dimensional imaging modalities in endodontics

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Teresa; Neelakantan, Prasanna [Dept. of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha University, Chennai (India)

    2014-09-15

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

  2. Three-dimensional imaging modalities in endodontics

    International Nuclear Information System (INIS)

    Mao, Teresa; Neelakantan, Prasanna

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome

  3. Magnetic resonance imaging-guided attenuation and scatter corrections in three-dimensional brain positron emission tomography

    CERN Document Server

    Zaidi, H; Slosman, D O

    2003-01-01

    Reliable attenuation correction represents an essential component of the long chain of modules required for the reconstruction of artifact-free, quantitative brain positron emission tomography (PET) images. In this work we demonstrate the proof of principle of segmented magnetic resonance imaging (MRI)-guided attenuation and scatter corrections in 3D brain PET. We have developed a method for attenuation correction based on registered T1-weighted MRI, eliminating the need of an additional transmission (TX) scan. The MR images were realigned to preliminary reconstructions of PET data using an automatic algorithm and then segmented by means of a fuzzy clustering technique which identifies tissues of significantly different density and composition. The voxels belonging to different regions were classified into air, skull, brain tissue and nasal sinuses. These voxels were then assigned theoretical tissue-dependent attenuation coefficients as reported in the ICRU 44 report followed by Gaussian smoothing and additio...

  4. Quantitative cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-06-01

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

  5. 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 ...

  6. Cone beam computed tomography in endodontic

    Energy Technology Data Exchange (ETDEWEB)

    Durack, Conor; Patel, Shanon [Unit of Endodontology, Department of Conservative Dentistry, King' s College London, London (United Kingdom)

    2012-07-01

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

  7. Cone beam computed tomography in endodontic

    International Nuclear Information System (INIS)

    Durack, Conor; Patel, Shanon

    2012-01-01

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

  8. X-ray computed microtomography of three-dimensional microcracks and self-healing in engineered cementitious composites

    International Nuclear Information System (INIS)

    Fan, Shuai; Li, Mo

    2015-01-01

    Concrete cracking and deterioration can potentially be addressed by innovative self-healing cementitious materials, which can autogenously regain transport properties and mechanical characteristics after the damage self-healing process. For the development of such materials, it is crucial, but challenging, to precisely characterize the extent and quality of self-healing due to a variety of factors. This study adopted x-ray computed microtomography (μCT) to derive three-dimensional morphological data on microcracks before and after healing in engineered cementitious composite (ECC). Scanning electron microscope and energy dispersive x-ray spectroscopy were also used to morphologically and chemically analyze the healing products. This work showed that the evolution of the microcrack 3D structure due to self-healing in cementitious materials can be directly and quantitatively characterized by μCT. A detailed description of the μCT image analysis method applied to ECC self-healing was presented. The results revealed that the self-healing extent and rate strongly depended on initial surface crack width, with smaller crack width favoring fast and robust self-healing. We also found that the self-healing mechanism in cementitious materials is dependent on crack depth. The region of a crack close to the surface (from 0 to around 50–150 μm below the surface) can be sealed quickly with crystalline precipitates. However, at greater depths the healing process inside the crack takes a significantly longer time to occur, with healing products more likely resulting from continued hydration and pozzolanic reactions. Finally, the μCT method was compared with other self-healing characterization methods, with discussions on its importance in generating new scientific knowledge for the development of robust self-healing cementitious materials. (paper)

  9. High spatial resolution three-dimensional mapping of vegetation spectral dynamics using computer vision and hobbyist unmanned aerial vehicles

    Science.gov (United States)

    Dandois, J. P.; Ellis, E. C.

    2013-12-01

    High spatial resolution three-dimensional (3D) measurements of vegetation by remote sensing are advancing ecological research and environmental management. However, substantial economic and logistical costs limit this application, especially for observing phenological dynamics in ecosystem structure and spectral traits. Here we demonstrate a new aerial remote sensing system enabling routine and inexpensive aerial 3D measurements of canopy structure and spectral attributes, with properties similar to those of LIDAR, but with RGB (red-green-blue) spectral attributes for each point, enabling high frequency observations within a single growing season. This 'Ecosynth' methodology applies photogrammetric ''Structure from Motion'' computer vision algorithms to large sets of highly overlapping low altitude (USA. Ecosynth canopy height maps (CHMs) were strong predictors of field-measured tree heights (R2 0.63 to 0.84) and were highly correlated with a LIDAR CHM (R 0.87) acquired 4 days earlier, though Ecosynth-based estimates of aboveground biomass densities included significant errors (31 - 36% of field-based estimates). Repeated scanning of a 0.25 ha forested area at six different times across a 16 month period revealed ecologically significant dynamics in canopy color at different heights and a structural shift upward in canopy density, as demonstrated by changes in vertical height profiles of point density and relative RGB brightness. Changes in canopy relative greenness were highly correlated (R2 = 0.88) with MODIS NDVI time series for the same area and vertical differences in canopy color revealed the early green up of the dominant canopy species, Liriodendron tulipifera, strong evidence that Ecosynth time series measurements capture vegetation structural and spectral dynamics at the spatial scale of individual trees. Observing canopy phenology in 3D at high temporal resolutions represents a breakthrough in forest ecology. Inexpensive user-deployed technologies for

  10. Telehealth in Schools Using a Systematic Educational Model Based on Fiction Screenplays, Interactive Documentaries, and Three-Dimensional Computer Graphics.

    Science.gov (United States)

    Miranda, Diogo Julien; Chao, Lung Wen

    2018-03-01

    Preliminary studies suggest the need of a global vision in academic reform, leading to education re-invention. This would include problem-based education using transversal topics, developing of thinking skills, social interaction, and information-processing skills. We aimed to develop a new educational model in health with modular components to be broadcast and applied as a tele-education course. We developed a systematic model based on a "Skills and Goals Matrix" to adapt scientific contents on fictional screenplays, three-dimensional (3D) computer graphics of the human body, and interactive documentaries. We selected 13 topics based on youth vulnerabilities in Brazil to be disseminated through a television show with 15 episodes. We developed scientific content for each theme, naturally inserting it into screenplays, together with 3D sequences and interactive documentaries. The modular structure was then adapted to a distance-learning course. The television show was broadcast on national television for two consecutive years to an estimated audience of 30 million homes, and ever since on an Internet Protocol Television (IPTV) channel. It was also reorganized as a tele-education course for 2 years, reaching 1,180 subscriptions from all 27 Brazilian states, resulting in 240 graduates. Positive results indicate the feasibility, acceptability, and effectiveness of a model of modular entertainment audio-visual productions using health and education integrated concepts. This structure also allowed the model to be interconnected with other sources and applied as tele-education course, educating, informing, and stimulating the behavior change. Future works should reinforce this joint structure of telehealth, communication, and education.

  11. NASA-VOF3D: A three-dimensional computer program for incompressible flows with free surfaces

    Science.gov (United States)

    Torrey, M. D.; Mjolsness, R. C.; Stein, L. R.

    1987-07-01

    Presented is the NASA-VOF3D three-dimensional, transient, free-surface hydrodynamics program. This three-dimensional extension of NASA-VOF2D will, in principle, permit treatment in full three-dimensional generality of the wide variety of applications that could be treated by NASA-VOF2D only within the two-dimensional idealization. In particular, it, like NASA-VOF2D, is specifically designed to calculate confined flows in a low g environment. The code is presently restricted to cylindrical geometry. The code is based on the fractional volume-of-fluid method and allows multiple free surfaces with surface tension and wall adhesion. It also has a partial cell treatment that allows curved boundaries and internal obstacles. This report provides a brief discussion of the numerical method, a code listing, and some sample problems.

  12. Real-time three-dimensional imaging of epidermal splitting and removal by high-definition optical coherence tomography.

    Science.gov (United States)

    Boone, Marc; Draye, Jean Pierre; Verween, Gunther; Pirnay, Jean-Paul; Verbeken, Gilbert; De Vos, Daniel; Rose, Thomas; Jennes, Serge; Jemec, Gregor B E; Del Marmol, Véronique

    2014-10-01

    While real-time 3-D evaluation of human skin constructs is needed, only 2-D non-invasive imaging techniques are available. The aim of this paper is to evaluate the potential of high-definition optical coherence tomography (HD-OCT) for real-time 3-D assessment of the epidermal splitting and decellularization. Human skin samples were incubated with four different agents: Dispase II, NaCl 1 M, sodium dodecyl sulphate (SDS) and Triton X-100. Epidermal splitting, dermo-epidermal junction, acellularity and 3-D architecture of dermal matrices were evaluated by High-definition optical coherence tomography before and after incubation. Real-time 3-D HD-OCT assessment was compared with 2-D en face assessment by reflectance confocal microscopy (RCM). (Immuno) histopathology was used as control. HD-OCT imaging allowed real-time 3-D visualization of the impact of selected agents on epidermal splitting, dermo-epidermal junction, dermal architecture, vascular spaces and cellularity. RCM has a better resolution (1 μm) than HD-OCT (3 μm), permitting differentiation of different collagen fibres, but HD-OCT imaging has deeper penetration (570 μm) than RCM imaging (200 μm). Dispase II and NaCl treatments were found to be equally efficient in the removal of the epidermis from human split-thickness skin allografts. However, a different epidermal splitting level at the dermo-epidermal junction could be observed and confirmed by immunolabelling of collagen type IV and type VII. Epidermal splitting occurred at the level of the lamina densa with dispase II and above the lamina densa (in the lamina lucida) with NaCl. The 3-D architecture of dermal papillae and dermis was more affected by Dispase II on HD-OCT which corresponded with histopathologic (orcein staining) fragmentation of elastic fibres. With SDS treatment, the epidermal removal was incomplete as remnants of the epidermal basal cell layer remained attached to the basement membrane on the dermis. With Triton X-100 treatment

  13. Three-dimensional, time-resolved profiling of ferroelectric domain wall dynamics by spectral-domain optical coherence tomography

    International Nuclear Information System (INIS)

    Haussmann, Alexander; Schmidt, Sebastian; Wehmeier, Lukas; Eng, Lukas M.; Kirsten, Lars; Cimalla, Peter; Koch, Edmund

    2017-01-01

    We apply here spectral-domain optical coherence tomography (SD-OCT) for the precise detection and temporal tracking of ferroele