アブストラクト(22巻3号:神奈川歯学)

神奈川歯学

Japanese

Title : 中性子ラジオグラフィーの歯科領域への利用の試み
Subtitle : 原著
Authors : 若尾博美, 東与光
Authors(kana) :
Organization : 神奈川歯科大学放射線学教室
Journal : 神奈川歯学
Volume : 22
Number : 3
Page : 506-518
Year/Month : 1987 / 12
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「I 緒言」中性子ラジオグラフィーとは中性子線による透過写真の撮影技術のことであり, X線やγ線と同様に中性子線が物体を透過する作用を利用した非破壊的な検査技術である. しかし, この中性子線はX線やγ線と異なり, 原子番号に対応しない特有の吸収係数を有していることが特長である. すなわち, 中性子線は水素原子にたいして, X線とは異なり大きな吸収係数をもっている. そのため, 水素原子を多く含有している生体組職の中性子ラジオグラムは, X線写真とは, まったく異なった像を示すことになる. この中性子ラジオグラムの撮影の試みは, 1956年にThewlisによって初めて工業用に行われた. また, 中性子ラジオグラフィーの医学への利用は, 1969年にBrownとParksによって初めて試みられた. 口腔領域への利用は, 1971年に初てBoyneらによって, 人間のエナメル上皮腫の下顎骨の撮影が試みられ, 従来のX線写真とは異なった所見が得られることを報告している.
Practice : 歯科学
Keywords : 中性子線, 中性子ラジオグラフィー, 吸収係数

English

Title : Potential Use of Neutron Radiography in Oral Region
Subtitle :
Authors : Hiromi WAKAO, Tomomitsu Higashi
Authors(kana) :
Organization : Department of Radiology Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 22
Number : 3
Page : 506-518
Year/Month : 1987 / 12
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : [Abrtract]: Neutron radiography is an imaging technique utilizing the ability of neutron beams to penetrate substances. This technique was first introduced to the medical world by Brown and Parks in 1969. In 1971, Boyne et al. visualized ameloblastoma of the mandible using this technique, and this was the first application of neutron radiography to the oral region. They stated that neutron radiography provided different images from those of conventional X-ray images. In this study, I tried to utilize neutron radiography in the field of dentistry using TRIGA II reactor at Institute for Atomic Energy, Rikkyo University. At first, I prepared a collimator for neutron radiography, and then evaluated the characteristics of this equipment in various ways. As a result, this collimator made for neutron radiography was determined to be useful for medical evaluation. In order to determine the feasibility of this technique in the field of dentstry, neutron radiograms of extracted tooth were compared with conventional X-ray radiograms taken at the same time. In the neutron radiogram, the enamel, which appears as a highly radiopaque image in the X-ray radiogram, was seen as a radiolucent image, while the dentine was observed as an radiopaque image in contrast with that seen in a X-ray image. I then prepared a three-dimentional graph with strengthened contrast in the neutron and X-ray images of teeth. I further found that the potentiality of neutron radiography in the field of dentistry, as the structures of teeth could be visualized using gadolinium, which has the highest attenuation coefficient for neutron beams among the atoms. The conclusion we obtained are summarized as follows : 1. Neutron radiography could provide images (resolution : 48μm) as clear as those of conventional X-ray images through our neutron collimator. 2. Transmittances through the enamel and dentin in a neutron radiogram were directly opposite to those in a X-ray images. 3. Infiltration of a contrast medium into teeth could be clearly visualized in detail by using gadolinium, which has a high attenation coefficient for neutron beams. 4. Differences in atomic components of teeth could be strengthened as density in neutron and X-ray radiograms. These results suggested a strong possibility that neutron radiography will be widely utilized in the field of dentistry in the future.
Practice : Dentistry
Keywords :