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PubMed1987

Three-dimensional structure of protein C inhibitor predicted from structure of alpha 1-antitrypsin with computer graphics.

The three-dimensional structure of a proteolytically modified protein C inhibitor, a member of the serine protease inhibitor superfamily, was constructed with computer graphics based on its amino acid sequence homology with that of the modified alpha 1-antitrypsin whose structure had been elucidated by X-ray crystallography. The intact form of protein C inhibitor was predicted with an alpha-carbon model based on its hydrophilicity and hydrogen bond pattern. Furthermore, a model of its interaction with activated protein C was constructed based on the structure of the complex between trypsin and its inhibitor, which had been determined by X-ray crystallography.

Amino Acid Sequence↗
PubMed1988

Computer graphics in medicine: a survey.

Increased interest is presently given to three-dimensional (3-D) medical applications due to simultaneous emergence of high-resolution imaging systems and computer graphics techniques. This paper intends to present a survey of this field together with discussion and prospective views. The general framework is composed of six parts: data acquisition and preprocessing, polygonal object representation, voxel description, system architecture, medical applications, and prospects. Data base acquisition includes characterization of imaging modalities and medical specificity. Preprocessing schemes are directed to improvements (filtering), windowing, and spatial anisotropy (linear or spline interpolation). The two following sections are devoted to descriptions of the main object representations. Particular emphasis is given to optimal contour approximation, surface triangulation, mathematical surfaces on one hand, and cuberille and voxel representations on the other. Display capabilities--hidden surface removal, surface normal shading, structure enhancement--and data base structuration--hierarchical and nonhierarchical (graph and tree encoding)--are, respectively, described. An overview of 3-D systems is further given (Section V), and features of medical applications are reviewed and gathered in basic functionalities, surgery, and radiotherapy specifications (Section VI). The last section provides some prospective views on reconstruction from a few projections, model-guided labeling, multimodality image overlay, and local image network. Some of these issues are illustrated by examples of 3-D images.

Computer Graphics↗
PubMed2004

[A psychopathological study on three-dimensional computer graphics (3DCGs): special reference to pictures made by a schizophrenic patient before and after the onset].

A patient with catatonic type schizophrenia drawing 3-dimensional computer graphics (3DCGs) before and after the onset is reported. His 3DCGs are discussed from the view of psychopathology. A 21-year-old male was admitted to our hospital. He was an art student. For three months before admission, he had been absorbed in drawing 3DCGs. When he was asked to draw handmade pictures by his teacher, he experienced a bizarre mood and took an overdose of aspirin. At the time of admission, he was in a stupor state, and was diagnosed with catatonic type schizophrenia. After admission, he exhibited excitement and disorganized speech. These symptoms disappeared after administration of neuroleptics, and he was discharged. The 3DCGs he drew before and after the onset revealed several special characteristics. First, the compositions of his pictures were too geometric and too precise. Secondly, the themes of his pictures changed from romantic before the onset to symbolic after it, and the styles changed from realistic to abstractive after the onset. Finally, histograms of the 3DCGs revealed many colors before onset, which converged to simple colors after. Therefore, it was suggested that the latent pathological process at the beginning of schizophrenia might be reflected in his 3DCGs. 3DCGs are a new type of fine art. They can express beautiful and cool images more simply than handmade pictures. Due to these features, artists can create images of their innerworld, with less effort and talent than picture drawings, by computer assistance. This case suggests that the geometric working space, change-free viewpoints, and computer assistance, which are characteristics of the methods in making 3DCGs may be suitable for schizophrenic artists to create images of their innerworld. However, being absorbed in making 3DCGs could also promote the latent schizophrenic process to the onset.

Adult↗
PubMed1989

[Attempt of analyzing the mandibular movement in three dimensions by computer graphics].

In clinic, simplified mandibular movement measuring devices are used for diagnosis of patients with stomatognathic dysfunction and recording maxillomandibular relation. It is difficult to understand mandibular movement in three dimensions from the path on the three planes, because the path of mandibular movement is in three dimensional space with time, not separately on each plane. The purpose of this study was to develop the three dimensional analyzing system by computer graphics. Mandibular movement was recorded by Mandibular Kinesiograph. The signals were sent to personal computer and the data were processed by the software. The basic specifications of the program were as follows: 1. Data could be observed from various viewpoints. 2. Necessary section of the simultaneous data could be displayed. 3. "C" was used for the software describing language. Following results were obtained: It was possible to analyze the path of mandibular movement in other coordinate axis and understand the path of mandibular movement in three dimensions more accurately.

Computer Graphics↗
PubMed1996

Computer graphic three-dimensional reconstruction of normal human embryo morphogenesis.

Three-dimensional computer graphic reconstructions of four human embryos at Carnegie stages 11 to 23 portray the relationships and dimensions of individual organ systems. This paper illustrates the cranial, neural, pharyngeal, gut, vascular and nephric architecture in these developing embryos. This technology can be applied to in situ hybridization and immunohistochemistry to map zones and times of developmental gene activity.

Embryo, Mammalian↗
PubMed1985

Computer graphics representation of levels of organization in tobacco mosaic virus structure.

Methods for simplifying computer graphics images of atomic models of complex macromolecular assemblies have been applied to the tobacco mosaic virus structure to display different levels of its organization. By constructing sharply outlined pictures of the parts of the virus particle with the image resolution reduced or with obscuring detail eliminated, aspects of the subunit packing and chain folding are distinctly illustrated.

Computers↗
PubMed1978

Computer-graphic representation of mandibular movements in three dimensions. Part I. The horizontal plane.

A computer-graphics simulation was developed to display the effects of mandibular movement patterns of both the maxillary and mandibular teeth in the occlusal plane. The many parameters affecting mandibular movement patterns may be varied selectively. The effects of these parameters on the pathways of movement described by the supporting cusps during occlusion can be graphically observed in the horizontal plane.

Art↗
PubMed1989

[Let's study exponential function related to anesthesiology by using computer graphics--Part I: Wash-out exponential function].

A computer simulation is used to analyze physical or biophysical changes related to anesthesiology mostly by computer oriented experts. Recent development in a personal computer and its program, however, has made it possible for more anesthesiologists to have an experience of computer analysis. For example, graphic expression of exponential functions can easily be obtained by using a computer program, such as "Graphnote" by Fukutake Pub. Co. In this literature, the author first explained the wash-out exponential function. Then estimation of changes in the hematocrit and serum protein concentration associated with blood loss during surgery was given as an example of biophysical phenomena related to anesthesiology, to which the wash-out exponential function is applicable for mathematical simulation. Besides, the author demonstrated the way to draw exponential function curves by using "Graphnote", so that the readers can express the curves by themselves.

Anesthesia↗
PubMed1989

Application of 3-D computer graphics for facial reconstruction and comparison with sculpting techniques.

Facial reconstruction has until now been carried out by the sculpting technique. This method involves building a face with clay or other suitable material on to a skull or its cast, taking into account appropriate facial thickness measurements together with information provided by anthropologists such as approximate age, sex, race and other individual idiosyncrasies. A method for facial reconstruction is presented using 3-D computer graphics and is compared with the manual technique. The computer method involves initially digitising a skull using a laser scanner and video camera interfaced to a computer. A face, from a data bank which has previously digitised facial surfaces, is then placed over the skull in the form of a mask and the skin thickness is altered to conform with the underlying skull. The advantage of the computer method is its speed and flexibility. We have shown that the computer method for reconstructing a face is feasible and furthermore has the advantage over the manual technique of speed and flexibility. Nevertheless, the technique is far from perfect. Further facial thickness data needs collecting and the method requires evaluation using both known control skulls and later unknown remains.

Computer Graphics↗
PubMed1987

Serial section reconstruction of the guinea pig outer hair cells as studied with a high-voltage electron microscope and a computer-graphic display.

The fine structural arrangement of the nerve endings on the guinea pig outer hair cells (OHCs) was studied by a serial sectioning technique by means of a high-voltage electron microscope and computer-graphic three-dimensional reconstruction. Sixty-nine series of consecutive sections were observed. Fifteen OHCs were located about 0.5 mm from the basal end (hook portion of basal turn) and 4 OHCs were seen at 6.0 mm, 20 OHCs at 8.0 mm (basal turn), 13 at 12.8 mm (second turn), 8 at 14.8 mm, 7 OHCs at 15.9 mm (third turn), and 2 OHCs at 17.5 mm (apical turn). Of 69 OHCs, 31 cells were from the first row, 22 from the second and 16 from the third row. The total number of nerve terminals on each OHC varied between 5 and 36. The OHCs with the least number of terminals were found in the hook portion, while the OHCs with the most numerous innervation were observed in the third row of the upper third turn. The afferent/efferent ratio (A/E ratio) of each OHC was evaluated and the OHCs were divided into two groups: Type A and Type B, depending upon the range of the A/E ratio. Thirty-five OHCs (50.7%) out of 69 were identified as being type A with an A/E ratio range of 0.5-1.5, while the remaining 34 OHCs (49.3%) were Type B cells with a greater A/E ratio than Type A cells. The detailed distribution of both types of cells was also studied along the entire length of the basilar membrane.

Animals↗
PubMed2002

Use of three-dimensional computer graphic animation to illustrate cleft lip and palate surgery.

OBJECTIVE: Three-dimensional (3D) computer animation is not commonly used to illustrate surgical techniques. This article describes the surgery-specific processes that were required to produce animations to teach cleft lip and palate surgery. MATERIALS AND METHODS: Three-dimensional models were created using CT scans of two Chinese children with unrepaired clefts (one unilateral and one bilateral). We programmed several custom software tools, including an incision tool, a forceps tool, and a fat tool. RESULTS: Three-dimensional animation was found to be particularly useful for illustrating surgical concepts. Positioning the virtual "camera" made it possible to view the anatomy from angles that are impossible to obtain with a real camera. Transparency allows the underlying anatomy to be seen during surgical repair while maintaining a view of the overlaying tissue relationships. Finally, the representation of motion allows modeling of anatomical mechanics that cannot be done with static illustrations. The animations presented in this article can be viewed on-line at http://www.smiletrain.org/programs/virtual_surgery2.htm. CONCLUSIONS: Sophisticated surgical procedures are clarified with the use of 3D animation software and customized software tools. The next step in the development of this technology is the creation of interactive simulators that recreate the experience of surgery in a safe, digital environment.

Child↗
PubMed1990

A new method for three-dimensional reconstruction from serial sections by computer graphics using "meta-balls": reconstruction of "hepatoskeletal system" formed by Ito cells in the cod liver.

A new method is described for three-dimensional reconstruction from serial ultrathin sections, using "meta-balls" as a primitive of object modeling in computer graphics (CG). We take advantage of the meta-ball's blobbiness characteristic and its rendering system for reconstructing images. The two-dimensional outline data from serial sections are converted into three-dimensional meta-ball data with a graphic editor, "Metack," by which we can check the correctness of the data conversion. Then the converted data are visualized on a color display with a CG rendering software, "Tracy". This reconstruction method is applied in studying the spatial distribution of Ito cells (fat storing cells) in the cod liver in relation to the blood capillary. By observing the reconstructed images, we can easily understand the three-dimensional relationship between the Ito cells and the blood capillary. The Ito cells surround the blood capillary and extend their cytoplasmic processes into the inter-parenchymal space to make a well-developed network system. These findings would support a concept of "hepatoskeletal system" formed by Ito cells in the cod liver. Therefore, we think that the meta-ball reconstruction method is useful in morphological study.

Animals↗
PubMed1990

Comparison of color flow and 3D image by computer graphics for the evaluation of carotid disease.

Morphologic characteristics and hemodynamics in the carotid artery were investigated in patients with stroke by use of Doppler color-flow analysis and three-dimensional (3D) analysis by computer graphics. The 3D imaging of the carotid bifurcation was reconstructed from a series of transverse B-mode images. Comparison of color-flow and 3D images demonstrated that wall configuration in vivo, dilation, and curvature play an important role in reversal of flow and stagnation at the carotid bifurcation. Furthermore, 3D analysis is very useful in mapping the distribution of the atheromatous plaques. The analyses suggest that it is important to investigate the wall configuration of the bifurcation in vivo on flow patterns, especially flow separation and stagnation, in relation to the development of atheromatous plaques.

Arteriosclerosis↗
PubMedDate not supplied

Three-dimensional reconstruction of colorectal tumors from serial tissue sections by computer graphics: a preliminary study.

BACKGROUND/AIMS: 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. METHODOLOGY: 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. RESULTS: 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. CONCLUSIONS: This technique may provide a new approach for pathological analysis of colorectal carcinoma.

Colonic Neoplasms↗
PubMed1998

Three-dimensional analysis and classification of arteries in the skin and subcutaneous adipofascial tissue by computer graphics imaging.

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.

Adipose Tissue↗
PubMed1994

Naphthalene black staining of granules of eosinophilic granulocytes: proposed mechanism of action using chemical blockade and computer graphics.

Histochemical staining of the granules of eosinophilic granulocytes and subsequent blockade of the reaction by alkaline benzyl was strongly suggestive that in its purified form, the diazo dye naphthalene black reacts with tissue sites containing high concentrations of arginine residues. Computer graphics modelling indicated that the sulfonate group of the dye reacts electrostatically with the guanidino functional group of arginine. This acid-base type reaction likely has a stoichiometric ratio of 2:1 in favor of the amino acid.

Amido Black↗
PubMed1982

An interactive computer graphic system for 3-d stereoscopic reconstruction from serial sections: analysis of metastatic growth.

An interactive computer graphic system has been developed for 3-D reconstruction of stained serial sections. The system has been used for 3-D reconstruction of portions of mouse lung containing melanoma nodules. A stereoscopic color picture of a wire model of the reconstructed object is produced. The volume, surface area, and sphericity index of structures such as tumor nodules can be computed.

Animals↗