アブストラクト(22巻4号:神奈川歯学)

神奈川歯学

Japanese

Title : 歯科用X線電子写真の歯周領域への応用 - 現像用電極電圧がEdge contract特性に及ぼす影響 -
Subtitle : 原著
Authors : 田村利之1),2), 堀俊雄1), 東与光2)
Authors(kana) :
Organization : 1)神奈川歯科大学保存学教室第二講座, 2)神奈川歯科大学放射線学教室
Journal : 神奈川歯学
Volume : 22
Number : 4
Page : 651-668
Year/Month : 1988 / 3
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「I. 緒言」 歯周疾患の診査, 診断および治療後の経過観察を行うにあたり, X線診査は重要な役割を果たしている. そして近年, 精密なX線画像情報を得ようとする試みから歯科用X線電子写真(Dental Xeroradiography : DXR)が開発され, 一般歯科臨床医にも利用されるようになった. DXRの臨床報告, 基礎的研究及びsystemの原理については, Gratt, White, 鹿島, Jerominらにより多くの報告がなされている. DXRは, 感光性銀塩の還元性を利用した従来の化学的写真法と異なり, 物理的プロセスを経て写した画像を再現させたものである. そして, 従来の銀塩フィルムの画像形成が, Broad area contrastに依存しているのに対して, DXRの画像形成は, 主にEdge contrastによるものといわれる. それ故, DXRはBroad area contrastは低いが, 独特の広い寛容度とEdge効果によって, 従来のフィルムよりも, 歯牙硬組織に関して多くの情報を写し出すことが可能と言われている.
Practice : 歯科学
Keywords : Dental Xeroradiography, 現像用電極電圧, Edge contrast, 臨床的診断価値, 情報量

English

Title : Application of Dental Xeroradiography for Periodontal Region - Influence of Development Electrode Voltage on Edge Contrast Quality -
Subtitle : Original article
Authors : Toshiyuki TAMURA1),2), Toshio Hori1), Tomomitu Higashi2)
Authors(kana) :
Organization : 1)Department of Periodontology, Kanagawa Dental College, 2)Department of Oral Radiorogy, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 22
Number : 4
Page : 651-668
Year/Month : 1988 / 3
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : Abstract : The strength of the edge dffect in dental xeroradiography (DXR) is regulated by the development-electrode-voltage (DEV) used during the development process. In an attempt to obtain an edge enhanced image suitable for each diagnostic purpose by controlling the DEV, I manufactured a variable DEV apparatus and modified the DXR 110 system in order to control the extent of edge enhancement. Through investigation of the relaation of between the DEV and characteristics of image quality (clinical diagnostic value, resolution, contrast characteristics, amount of information) in DXR, I reached the following conclusions : 1. An image with enhanced edge contrast (low DEV) provided high levels of visual diagnostic value for the lamina dura, periodontal ligament space, furcation involvements and root shape while that with weak edge contrast (high DEV) was less useful for diagnostic imaging of bone trabeculae and the interdental alveolar bone crest. 2.Broad area contrast exhibited a higher sensitivity, increased fogging and decreased gamma with increasing DEV. 3. Edge contrast formed a broader white gap and higher peak-to-peak as the DEV was reduced. A clear edge weve image with a maximum and minimum density was not delineated under the DEV of 1100V and 1300V. 4. Resolution dependency in the DEV range of 1300-1700V was not noted in the specific spatial frequency zone (2.0-8.0 LP/mm) used in the present study. 5. The amount of physical information obtained on bone trabeculae was greater in images formed under high DEV than in those under low DEV. These results show the images suitable for various diagnostic purposes could be obtained by controlling the edge contrast using variable DEV equipment in dental xeroradiography.
Practice : Dentistry
Keywords : Dental Xeroradiography, Edge contrast