巻号一覧
20 巻 (1980)
- 4 号 p. 279-
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- 2 号 p. 99-
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20 巻, 2 号
選択された号の論文の8件中1～8を表示しています
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第二報散乱線附加による線量軽減川津 泰一, 丹羽 克味, 金井 良維, 山中 延元1980 年 20 巻 2 号 p. 99-105
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーWhen intraoral roentgenogram is taken by using some scattering medium adhered to the back of the film, the primary X-ray enters into the scattering medium after passing through the object and the film to emit secondary X-ray. Thus occurred secondary X-ray increases the film density, with an elevation of the film sensitivity as a result of it.
We carried out a basic experiment in order to decrease the patient dose by utilizing the above described principal in intraoral roentgenography. As the film, Fuji dental film was used. As the scattering material, the 50:50 (weight basis%) mixture of molybdenum powder and paraffin wax was prepared to the size of intraoral film, the thickness being 5mm. Thus prepared scattering medium was adhered to the film and intraoral roentgenography was performed. It was found that the local exposure of patients could be decreased by about 20% as compared to the conventional intraoral roentgenography.抄録全体を表示PDF形式でダウンロード (1302K) -
第三報液体シンチレーターの使用佐藤 圭三, 川津 泰一, 丹羽 克味, 金井 良維1980 年 20 巻 2 号 p. 106-111
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーIn order to decrease X-ray exposure in intraoral roentgenography, we prepared a screen for trial using an organic scintillator which is currently applied for liquid scintillation counting, aiming at reducing X-ray exposure as far as possible without so much reduction in sharpness and with cost cheap enough to make it disposable, and made a study on its properties. The screen was prepared using BBOT and PPO as the organic scintillator and polyvinyl acetate as the binder. In addition, a screen containing organic zinc was also prepared. The fluorescence from the screen for trial was about one fifth of that from FS screen, with relative sensitivity about twice of that of Fuji dental film. With respect to the characteristics of tube voltage, the relative sensitivity became higher with an elevation in tube voltage. It was found that MTF revealed not so much reduction, showing a tendency similar to that of Fuji dental in the high frequency area. In the roentgenography of the maxilla, the exposure time could be reduced to less than one half of that required when the screen for trial was not used. Little or no reduction in sharpness was observed as compared to the roentgenogram taken with Fuji dental film. Since the required amount of scintillator itself is small, the screen can be prepared with low cost, making it possible to use it as a disposable screen.抄録全体を表示PDF形式でダウンロード (1503K) -
小寺 吉衛, 藤田 實, 谷本 啓二, 和田 卓郎, 山根 由美子, 竹内 知行1980 年 20 巻 2 号 p. 112-120
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーThe image quality of panoramic radiography using the intraoral x-ray tube was examined. The size, line spread function (LSF) and modulation transfer function (MTF) of its focal spot were measured, and were compared with those of an ordinary dental x-ray tube having nominal focal spot size of 0.8mm.
The pinhole images were taken for three directions of x-ray beams. The shape of the effective focal spot was an isosceles triangle having right angle. And the shape became gradually a circle with decrease of the angle of the x-ray beam to the axis of the tube. The LSFs in the x direction (perpendicular to the axis of the tube) hardly depend on the angle, but those in the y direction (parallel to the axis of the tube) are larger as the angles become smaller. The MTFs in the x direction scarcely change, and those in y direction are reduced in proportion to the decrease of the angles.
The MTFs of the intraoral x-ray tube technique were inferior to those of the conventional technique. This reason is that the focal spot size of the intraoral x-ray tube was extremely larger than the nominal focal spot size and the magnification of the intraoral x-ray tube technique was much larger than that of the conventional technique. Therefore, it is necessary to reconsider the focal spot size of the intraoral x-ray tube in company with the measuring method.抄録全体を表示PDF形式でダウンロード (1267K) -
清水谷 公成, 田中 義弘, 諸井 英二, 安達 泉, 古跡 養之真1980 年 20 巻 2 号 p. 121-130
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーSixty-five cases of lower gingival cancer (squamous cell carcinoma in all cases) have been examined roentgenographically and histologically in attempt to delineate the clinical significance of classifing the roentgenographic features of the mandible. Then we analized these prognosis.
The results obtained were as follows:
1) The most frequent area of tumor mass was the molar region (77%). We classified 3 roentgenographic features; pressure type (31%), permeated type (29%), moth-eaten type (23%) and nonpredominantly bony destruction (17%).
2) Permeated type and moth-eaten type tended to appear histologically moderate or poor in differentiation.
3) Permeated type and moth-eaten type tended to appear T3 case.
4) Moth-eaten type had poorer prognosis.抄録全体を表示PDF形式でダウンロード (6130K) -
401例の分析安達 泉, 江原 昌弘, 諸井 英二, 清水谷 公成, 岡本 考司, 田中 義弘, 古跡 養之真1980 年 20 巻 2 号 p. 131-137
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーThis report is a clinical observation based on 401 patients who visited on Department of Oral Radiology, Osaka Dental University from April 1970 to March 1975, because of mandibular fracture.
The purpose of this paper is to clarify the site of occurrence of mandibular frature and the pattern of fracture mode.
The results are summarized asfollows:
1) The number of annual patients in 1975 increased as one and a half times many as that in 1970.
2) Fractures in male were found as four times as those in female.
3) More than half of the patients were 10 to 30 years of age.
4) The fractures were caused by traffic accident, accident in working and violent fall.
5) The total number of fracture lines in 401 patients with mandibular fracture were 670 lines, and 1.67 fracture lines per person were observed.
6) Condylar process, cuspid-premolar and anterior regions were most frequently affected, mandibular angle and molar region were following site, ascending ramus and coronoid region were less affected.
7) When first fracture line in anterior or cuspid-premolar region was found, the second or the third fracture lines were often found in the condylar process.
8) The simple bone fracture line were often found in molar region or madibular angle.
9) More than half of condylar fracture were combined with fractrue of the anteior region or fractures of contralateral condylar process.抄録全体を表示PDF形式でダウンロード (736K) -
内海 潔, 江原 昌弘, 諸井 英二, 山本 知則, 古跡 養之真1980 年 20 巻 2 号 p. 138-139
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーPDF形式でダウンロード (1238K) -
松沢 輝子, 五島 洋太, 山本 昭, 瀬戸 完一1980 年 20 巻 2 号 p. 140-141
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーPDF形式でダウンロード (871K) -
1980 年 20 巻 2 号 p. 157-218
発行日: 1980年
公開日: 2010/10/21
ジャーナル フリーPDF形式でダウンロード (6064K)
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