| Project/Area Number |
02670889
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
外科・放射線系歯学
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
DOMON Masaharu Tokyo Medical and Dental University, Department of Dental Radiology and Radiation Research, Associate Professor, 歯学部, 助教授 (60014198)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHINO Norio Tokyo Medical and Dental university, Department of Dental Radiology and Radiatio, 歯学部, 助手 (70220704)
HONDA Eiichi Tokyo Medical and Dental university, Department of Dental Radiology and Radiatio, 歯学部, 助手 (30192321)
KURABAYASHI Tohru Tokyo Medical and Dental University, Department of Dental Radiology and Radiatio, 歯学部, 助手 (60178093)
SASAKI Takehito Tokyo Medical and Dental University, Department of Dental Radiology and Radiatio, 歯学部, 教授 (90013896)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Sjogren's syndrome / Autoimmune disease model mouse / Sigalogram / Fractal dimension / Tree pattern / 放射線免疫学的治療法 / 画像解析 / 膨脹画像処理法 |
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| Research Abstract |
The research results are summarized into three points as follows.
The method of fractal dimension measurements of 1-dimension shapes has been established by using dilation algorism of image analysis and published as listed below. X-ray sialograms of Sjogren's syndrome patients were measured by the dilation method and found to be characterized by lowered fractal dimensions of parotid gland ductal systems. Briefly, the averaged fractal dimension of sialograms of normal subjects was 1.64 and that of Sjogren's syndrome was 1.39. The lowered fractal dimension indicates the decreased number of parotid ducts or the simplification of the ductal patterns of Sjogren's syndrome patients. At present, the presence of punctuated images in their sialograms is adopted as the criteria for diagnosis of Sjogren's syndrome. Since the ductal changes of parotid glands precede the appearance of the punctuated images at an early phase of the disease, the fractal dimension of the ductal patterns is expected to
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serve as a better indicator for the progression of the disease.
An investigation of sialograms and histology of the mouse strain, NZB/WF1 which serves as a model of Sjogren's syndrome and develops autoimmune disease with its age indicated that the ductal pattern changes of parotid glands and increased numbers of polyploid acinar cells in the glands precede the focus formation, i. e. infiltration of lymphocytes into the striated duct regions of the glands. The focus formation is adopted as a pathological criterion for the autoimmune disease. That is, the parenchyma changes appear earlier than mesenchyma changes in the disease and so the former is expected to be a better indicator for the diagnosis.
Fractal dimesions of duct branching systems are expected as a useful indicator for the diagnosis of Sjogren's syndrome and so it is required to understand what modulates their measured values in practical ductal patterns of the parotid gland. The dichotomus tree patters were drawn by computer graphics using parameters of branching angle, branch ratio, length of stem, and number of branchings. The fractal dimensions of the tree patterns were analyzed by varying the parameters, of which measurements were carried out by using the dilation method as mentioned above. The fractal dimension was found to be depending on the parameter in a very complexed fashion and the factors to modulate the dimension are the size of a branch unit, weight of stem pixels compared with branch point of the unit, branch angle, branch ratio, interference between branch units, number of branchings, interference and pixel-weight contribution of branch units at different branch orders. These factors' contributions are furthermore influenced by scales of a measure used to recognize the fractal dimensions of the tree-patterns. A more general conclusion is that the fractal dimension of a practical shape depends on a scale of a measure used and so not an invariant value. Therefore, it is essential to mention the scale of a measure used when the fractal dimension value is presented. Less
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