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Tomography System (tomography + system)
Selected AbstractsIdentification of root canals in molars by tuned-aperture computed tomographyINTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2000R. Nance Abstract Aim To compare the tuned-aperture computed tomography system of imaging to conventional D-speed film for their ability to identify root canals in extracted human molars. Methodology Thirteen maxillary and six mandibular human molars were mounted in acrylic blocks to simulate clinical conditions by surrounding the teeth with a radiodense structure. The teeth were then imaged with conventional D-speed film using a standard paralleling technique, and with a modified orthopantomograph OP100 machine using a Schick no. 2 size CCD sensor as the image receptor. The source images were registered and TACT slices were generated using TACT WorkbenchÔ Software. Three observers were asked to identify the number of canals in the conventional film group and the TACT image group using specific criteria. Ground truth was established by cross-sectioning the teeth at the coronal, middle, and apical thirds of the roots and directly visualizing the root canal morphology. Results TACT imaging detected 36% of 4th canals in maxillary molars and 80% of third canals in mandibular molars. Conventional film detected 0% of fourth canals in maxillary molars and 0% of third canals in mandibular molars. The differences in canal detection between the two techniques were statistically significant (Wilcoxon matched pair sign rank test, P = 0.001). Conclusions In this study, the TACT system of digital imaging was superior to conventional film in the detection of root canals in human molars and may be useful for the detection of root canals that will probably be missed upon conventional X-ray examination. [source] Development of dento-maxillofacial cone beam X-ray computed tomography systemORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 2003K Yamamoto Abstract Authors, Yamamoto K, Ueno K, Seo K, Shinohara D We have developed a cone beam X-ray computed tomography (CT) system to make more accurate three-dimensional (3-D) images for diagnosis of dento-maxillofacial region. The developed system has sufficient spatial resolution, resolution of 3-D images and image distortion for diagnosis of dento-maxillofacial region. [source] USING OPTICAL COHERENCE TOMOGRAPHY TO EXAMINE THE SUBSURFACE MORPHOLOGY OF CHINESE GLAZESARCHAEOMETRY, Issue 5 2009M.-L. YANG Optical coherence tomography (OCT), a new method for ceramics research, is a nondestructive, three-dimensional tomography system, which provides subsurface morphology visualization of samples based on the refractive index or dielectric constant differences in the target specimen. In this study, seven shards from different Chinese kilns of Song and Yuan dynasties (10,14th centuries) were scanned to visualize the subsurface morphology of their glazes. The images revealed unique phase assemblage modes in different samples. The results suggest OCT may be used to identify ceramics and provide information about their manufacturing technology. [source] Splitting a large software repository for easing future software evolution,an industrial experience report,JOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 2 2009Marco Glorie Abstract Philips Medical Systems produces medical diagnostic imaging products, such as magnetic resonance, X-ray and computed tomography systems. The software of these devices is complex, has been evolving for several decades and is currently a multi-MLOC monolithic software repository. In this paper we report on splitting a single software repository into multiple smaller repositories so that these can be developed independently, easing the software's evolution. For splitting the single software repository, we set up two experiments that involve well-known analysis techniques, namely formal concept analysis and clustering. Because of the sheer size of the monolithic software repository, we also propose to use a ,leveled approach', which implies that the analysis technique is applied in several iterations, whereby in some iterations only part of the application is subjected to the analysis technique. Unfortunately, both analysis techniques failed to produce an acceptable partitioning of the monolithic software repository, even if they are combined with our newly proposed leveled approach. We provide a number of valuable lessons learned, which might prevent others from falling into the same pitfalls. Copyright © 2009 John Wiley & Sons, Ltd. [source] | ||||||||||